Science topic

Hydroxides - Science topic

Inorganic compounds that contain the OH- group.
Questions related to Hydroxides
  • asked a question related to Hydroxides
Question
1 answer
Debye-Huckel theory fails for such increased concentrations. On which assumption, researchers assume activity coefficient of hydroxide ions as 1.
Relevant answer
Answer
Please, read this paper and you will understand how complex is your question. The, we'll discuss it.
  • asked a question related to Hydroxides
Question
1 answer
When we want to calculate the hydrogen diffusion coefficient in a KOH electrolyte solution using impedance, is hydroxide being counted or hydrogen?
Relevant answer
Answer
Magnesium hydride is a good option to store hydrogen.
  • asked a question related to Hydroxides
Question
2 answers
As a rule, when synthesizing geopolymers based on low-calcium aluminosilicates, caustic alkalis are used, i.e. hydroxides of alkali metals Na and K. Why do hydroxides of alkaline earth metals Ca and Mg not work for these geopolymers?
Relevant answer
Dear Hasan Altawil,
Thanks a lot for your answer
  • asked a question related to Hydroxides
Question
1 answer
I'm following a paper for their HPLC methodology, but I'm having a hard time understanding how to make mobile phase A.
To quote:
"Mobile phase A is a mixture containing 0.2% potassium dihydrogen phosphate solution and 20% tetrabutylammonium hydroxide solution (200:1, v/v)..."
I want to make a total of 500ml mobile phase solution.
My questions are:
1. How many grams or ml solution of potassium dihydrogen phosphate I should prepare?
2. How many grams or ml solution of tetrabutylammonium hydroxide I should prepare?
3. What does (200:1, v/v) mean?
Molecular weight
Potassium dihydrogen phosphate (KH2PO4): 136.09
tetrabutylammonium hydroxide (C16H37NO): 259.47
I have very little background in chemistry and this is very confusing for me. Any advice would be helpful. Thank you!
Relevant answer
Answer
Hi.
Here is a step-by-step instructions how to make the mobile phase:
Step-1: Make 0.2% potassium dihydrogen phosphate solution.
Transfer 2.0 grams of potassium dihydrogen phosphate into a 1L volumetric cylinder or volumetric flask. Add approximately 500 mL of water. Add a stir bar and dissolve the salt (shaking can be used instead). Remove the stir bar, if used, and fill to the 1L mark with water. [optional but desired, filter through 0.45 µm or finer filter].
Step-2: 20% tetrabutylammonium hydroxide solution
Option-a) Purchase 40% tetrabutylammonium hydroxide solution in water, such as MillioporeSigma's product ID 178780. Into a vial or a beaker, mix 10.0 mL of the 40% solution with 10.0 mL of water.
Option-b) Purchase tetrabutylammonium hydroxide 30-hydrate solid (Mw~800), such as MilliporeSigma's product ID 86859. Transfer 2.96 grams of the hydrate solid into a 10 mL volumetric flask. Add a few mL of water and shake or sonicate to dissolve. Allow to cool to room temperature, if sonicated, then fill to the mark with water. [optional but desired, filter through 0.45 µm or finer filter].
The 2.96 grams accounts for the 30 water molecules present in the hydrate (if anhydrous salt is used - not sure if sold - you would need 2.0 grams instead).
Step-3: Mobile Phase-A preparation
Mix 500 mL of the 0.2% potassium dihydrogen phosphate solution from Step-1 with 2.5 mL of the 20% tetrabutylammonium hydroxide solution from Step-2. This will give you a final ratio of 200:1 v/v.
Notes:
1% solution means 1.0 gram into 100 mL. You can downscale from here to make any percent you want.
200:1 v/v means 200 parts from component-1 mixed with 1 part of compotent-2 (for example, 200 mL + 1 mL). The v/v part reads as "volume/volume".
  • asked a question related to Hydroxides
Question
1 answer
It is observed that MnO2 stores charge by means of potassium (+) ion while cobalt oxide store energy by hydroxide (-) ion while both materials are employed as cathodes in separate systems.
Relevant answer
Answer
Hey there Abin Philip!
So, the reason why some materials store energy through cations while others through anions in a two-electrode system boils down to their inherent chemical properties and electrochemical behavior.
In the case of MnO2, it's known to store charge by utilizing potassium cations (+) in its structure. This is because MnO2 has a crystal lattice structure that can accommodate the insertion and extraction of these potassium ions during the charge and discharge cycles.
On the other hand, cobalt oxide (CoO) stores energy by utilizing hydroxide anions (-) in its structure. The hydroxide ions can be reversibly inserted and removed during the charging and discharging process, which enables cobalt oxide to store energy efficiently.
Now, the reason for this difference lies in the specific chemical composition and crystal structure of these materials. MnO2 and cobalt oxide have different chemical structures and properties, which determine how they interact with ions during the electrochemical processes.
In simpler terms, think of it like this: MnO2 prefers to work with positively charged ions (cations) because of its structure, while cobalt oxide is better suited to work with negatively charged ions (anions) due to its own unique structure.
So, it's all about the chemical makeup and the way these materials are designed to interact with ions during energy storage. Pretty cool Abin Philip, right? Let me know if you Abin Philip want to dive deeper into this!
  • asked a question related to Hydroxides
Question
2 answers
I'm currently working on the PMS activation so I wonder about the difference between using MOF, metal oxide, or metal hydroxide as a heterogeneous catalyst, and what are the better ones. I'm looking forward to your answer. I truly appreciate your helping.
Relevant answer
Answer
Dear Meg Nguyen
Heterogeneous catalysts derived from transition metals can exhibit varying properties and performance depending on their composition and structure. Here's a comparison of catalysts derived from metal oxides, metal hydroxides, and metal-organic frameworks (MOFs), along with their advantages and disadvantages:
Metal Oxides:
Advantages:
High thermal stability and robustness.
Wide availability of transition metal oxides.
Tunable surface properties through modification of the metal oxide composition or doping.
Can provide strong Lewis acid or base sites for catalytic reactions.
Disadvantages:
Limited surface area, which can affect catalytic activity, especially for reactions requiring high surface area.
May suffer from sintering or agglomeration during catalytic reactions, leading to loss of active surface sites and reduced catalytic efficiency.
Limited control over morphology and surface structure, which can impact catalytic selectivity and stability.
Metal Hydroxides:
Advantages:
Can serve as precursors for metal oxide catalysts through controlled thermal decomposition.
Some metal hydroxides exhibit high surface area and porosity, enhancing catalytic activity.
May offer tunable surface chemistry and reactivity through surface functionalization or modification.
Disadvantages:
Susceptible to hydrolysis and dissolution under certain reaction conditions, leading to loss of catalytic activity and stability.
Limited thermal stability compared to metal oxides.
Surface hydroxyl groups can act as adsorption sites for reactants, but may also lead to catalyst deactivation due to surface poisoning or blocking.
Metal-Organic Frameworks (MOFs):
Advantages:
High surface area and porosity, providing abundant active sites for catalysis.
Tailorable pore size and surface functionality, enabling precise control over catalytic properties and selectivity.
Potential for incorporation of multiple metal centers and organic linkers to create multifunctional catalysts.
Enhanced stability compared to traditional porous materials under certain reaction conditions.
Disadvantages:
Limited thermal stability at high temperatures, which can restrict their use in catalytic reactions requiring elevated temperatures.
Susceptible to structural collapse or framework decomposition under harsh chemical environments or in the presence of moisture.
Synthesis of MOFs with desired properties can be challenging and may require specialized techniques.
Cost considerations, as some MOF synthesis methods can be relatively expensive compared to traditional metal oxide or hydroxide catalysts.
In the context of PMS (peroxydisulfate) activation, each type of heterogeneous catalyst may offer unique advantages and challenges. Metal oxides and hydroxides may provide robust catalytic activity for PMS activation, especially for reactions requiring high thermal stability. On the other hand, MOFs could offer tailored pore structures and surface functionalities, potentially leading to enhanced catalytic performance and selectivity. The choice of catalyst ultimately depends on factors such as the specific reaction conditions, desired catalytic activity, stability requirements, and availability of suitable catalyst materials.
  • asked a question related to Hydroxides
Question
1 answer
I have recently uploaded a research paper (Feasibility study of replacing currently used freons with Ammonium Chloride and Barium Hydroxide.
(https://nepjol.info/index.php/hijost/article/view/61132) on research gate and shared on facebook. Many of my well-wishers wish to study the paper but they were unable to find the article. What is this issue
Relevant answer
Answer
However, I guess you mean that it cannot be found with a Google search. The problem is that it can take days to weeks until Google's automated crawler will find this page in the Internet. It is technically not possible to scan the complete Internet each day to find new pages. You just have to be patient until Google will find your paper in ResearchGate. Google Scholar has got it already (https://scholar.google.de/scholar?hl=en&as_sdt=0%2C5&q=Feasibility+study+of+Replacing+Currently+used+Freons+with+Ammonium+Chloride+and+Barium+Hydroxide+for+Freezing+System&btnG=), possibly from www.nepjol.info/index.php/hijost/article/view/61132.
  • asked a question related to Hydroxides
Question
1 answer
I think it can be Mn hydroxide.
Relevant answer
Answer
I did not any analysis on this Mn ore deposit outcrop so just I think it can be Mn hydroxide.
  • asked a question related to Hydroxides
Question
1 answer
The samples are Periwinkle shells, clam shells, whelks shells and snail shells. they were chemically activated by Sulphuric acid and Potassium Hydroxide.
The SEM and FTIR imagery is required for my Thesis.
Relevant answer
You can check in with Allschoolabs scientific. Equipped with some of Nigeria's Best equipment currently . See Details - analysis.allschoolabs.com
  • asked a question related to Hydroxides
Question
1 answer
Do defects of CNTs get occupied spontaneously with carboxylic acid and hydroxide functions only by being exposed to air?
Relevant answer
Answer
Not every defect will react the same way. Essentially you can check out the chemistry of small aromatic compounds: if the defect looks like a compound which gets hydrolyzed to COOH or COH, that will also happen there.
  • asked a question related to Hydroxides
Question
2 answers
During a green synthesis of Copper oxide nanoparticles using a given plant extract, Nano Copper hydroxide sulfate and nano copper oxide were formed . the xrd showed the presence of both( cuo and the hydroxide sulfate)
First i used NaOH to manipulate pH. Did the Nano copper hydroxide sulfate was formed due to the presence of NaOH or as a result of the used plant extract?
Second in the xrd, there are common peaks between both compounds. how can i realize if these peaks belongs to a given compound rather than the other?
Relevant answer
Answer
Check out the article. There are answers to all your questions.
  • asked a question related to Hydroxides
Question
5 answers
Does anyone can offer a route to produce aluminium hydroxide nanoparticles in chloride solution especially using precipitation or hydrothermal method?
Relevant answer
Answer
Farhad Moosakazemi Examine the Pourbaix diagram of aluminum easily found in the literature or on Research Gate. For example:
  • asked a question related to Hydroxides
Question
2 answers
I am currently developing my SOP for sample injection into our soon-to-arrive Biorad Aminex HPX-42A column. The plan is to use HPLC grade water at 85°C for eluent. Based on the "Use and Care" guidelines provided for the columns, the HPX-42A has an acceptable pH range of 6-8. However, we intend to inject samples with a pH as low as 2. I would like to carry out neutralisation on the samples, but want to ensure that I am not causing any issues with my neutralising agent selection.
Are their limitations for neutralising agent use in samples to be injected into Aminex columns?
I am aware that there's a potential problem with counter ion replacement in these ligand exchange columns - if the cation that could exchange with the silver is in salt form, does this still pose a risk?
With a refractive index detector, there's a potential for eluent density fluctuation with salts that remain in the solution. Should I therefore use a neutralising agent whose salts precipitate? (Barium Hydroxide?)
Any suggestions or comments would be appreciated.
Relevant answer
Answer
Thank you very much Bruce Neagle
  • asked a question related to Hydroxides
Question
3 answers
Can it help to improve the durability and corrosion resistance of the catalyst by minimizing the formation of surface hydroxide species or dissolution of the catalyst material?
Please cite some reference.
Relevant answer
Answer
Your question is too general to be answered. If you are asking about electrochemical water oxidation, the anode surface always has a high positive potential.
  • asked a question related to Hydroxides
Question
1 answer
In theory, aluminum oxide as an amphoteric oxide can be soluble in strong alkali, and I used Y-alumina, but the experiment found that it is completely insoluble. Please find an explanation and dissolution method.
Relevant answer
Answer
It should be soluble, but the rate of dissolution varies based on particle size and thermal history. "Completely insoluble" is not likely; you may want to separate the supernatant liquid from the solution by filtration or centrifugation and analyze for Al by IPC, to get a sense of the actual rate of dissolution.
Also, of course, dissolution rate can be greatly enhanced by temperature, so it's worth trying hot or even boiling base solution (but be careful about self-protection from caustic droplets).
  • asked a question related to Hydroxides
Question
2 answers
I mixed potassium hydroxide with pre-carbonized biochar in a ratio of 3 to 1. I heated the mixture in a tube furnace at 5 degrees/min, 800 degrees for 2 hours. Why did the activated biochar white in color and stick to the crucible? and there was an emission of large quantities of the sample. Please, I need answers urgently.
Relevant answer
Answer
You probably removed all the C and melted the KOH. The KOH may have also reacted with CO2 to form the carbonate. Liquid KOH dissolves SiO2 which I'm guessing the crucible was composed of
  • asked a question related to Hydroxides
Question
12 answers
I am preparing LDH with co-precipitation method using aluminium chloride and calcium chloride. Upon addition of NaOH to AlCl3.6H2O and CaCl2.6H2O, not only LDH but also Al(OH)3 is formed. How should I prevent formation of this hydroxide?
Relevant answer
Answer
Dear Maryam,
The following articles may be of help to you. Of course, the M+2/M+3 ratio is essential but pH is critical since it will determine the solubility of the M(OH)2 or M(OH)3 phases.
1- Robertson J. Geochemical characteristics of aluminum and magnesium secondary mineral phases in uranium mill tailings. Ph.D. University of Saskatchewan. 2017.
  • asked a question related to Hydroxides
Question
2 answers
Hi! I need to etch silicon out from glass surface and at the moment I have no acces to KOH. Can I use other hydroxides such as NaOH or Ca(OH)2 and expect similar results?
Relevant answer
Answer
Silicon etchant with hydroxide but without both HF and KOH. ― You may wanto consider: NaOH aq. + (I2, Br2, NaClO3, or Na2Cr2O7·2H2O aq.).
  • asked a question related to Hydroxides
Question
2 answers
I am attempting to replicate a HPLC method for the determination of water-soluble vitamins and the mobile phase consists of 0.1M Phosphate buffer (pH 7).
The paper states that they made up the buffer by "the addition of 0.1 mol/L potassium dihydrogen phosphate and 0.1 mol/L potassium hydroxide"
However, I would usually make up this buffer by adding potassium phosphate dibasic and potassium phosphate monobasic (in the correct quantities) to water.
Are these two methods the same and would the resultant buffer be the same?
Thank you!
  • asked a question related to Hydroxides
Question
2 answers
I have two questions.The first is, is a proportion of water taken to the binder in the geopolymer industry, as in ordinary concrete, or do we rely only on additional water, hydroxide water, and silicate water?Is the superplasticizer taken as a percentage of the binder or something else? as in ordinary concrete, or do we rely only on additional water, hydroxide water, and silicate water?Is the superplasticizer taken as a percentage of the binder or something else?
Relevant answer
Answer
Dear Raheem,
you are wronging the fundamentals of geopolymerization.
To change the workability of every GP material you must understand how happened the reactions. So check your raw materials and learn about the mixing method that are completely different from OPC technology or from every alkali activated materials, that are still hydraulic so can have some feature close to the Portland recipes. GP are mineral polymers without crystal water inside.
Only very few admixtures work with GP materials but to fluidize at best can be used a proper balancing of the precursor and few % of extra water maintaining in this way under control (very low) the shrinkage.
No additives are necessary for having self compacting and water to something ratio are numbers with no importance. Can be evaluated a ratio between liquid reagent (alkaline or acid for GP the selection depend only on the costs and because of the application) and precursor in powder to know just how fine and reactive is that specific precursor but isn’t connected to hardening time, mechanical strength development or other important parameters.
Check at www.geopolymer.org for more detailed informations it’s the site where write directly Professor Davidovits the father of Geopolymer Technology.
Best regards
Alex Reggiani
  • asked a question related to Hydroxides
Question
4 answers
Hi,
I want to convert my quaternary ammonium iodide to its acetate form. In literature I usually see that people start from the bromide salt and then convert it to acetate. Does anyone know why it is not common to use iodide as the substrate? And in case I want to use my iodide as the starting material is the ion exchange from iodide to hydroxide using a methanolic solution and an ion exchange column packed with strong basic resin (OH form) efficient enough? Because if it is efficient then I can react the hydroxide with stoichiometric amount of acetic acid.
Relevant answer
Answer
  • asked a question related to Hydroxides
Question
2 answers
I want to know how I would prep 500ml of 25% weight/volume potassium hydroxide. From this stock, how would I perpare a 0.1M working solution?
If you could give as much detail on working out too please. I'd like to understand.
Relevant answer
Answer
  • asked a question related to Hydroxides
Question
1 answer
I want to do ICP-MS and ICP-AES of the solution having pH >7. The alkalinity of the solution by Na and K hydroxides.
Relevant answer
Answer
There is no specific reason you can't analyse alkaline/basic solutions, for example tetramethyl ammonium hydroxide (TMAH) is used for blood and milk analysis, BUT you have to be sure you have:
  • calibrated the instrument with a similar matrix to the samples (0.1% TMAH for example)
  • complete dissolution of your samples (no precipitates)
  • diluted to a realistic concentration for analysis (<0.2% total dissolved solids, and:
  • don't even try to measure the Na and K used to adjust the alkalinity, you will saturate the detector and probably not get a worthwhile value by ICP.
If you calibrate with 1% nitric acid from 1-250 µg/L for your elements of interest, but measure an alkaline sample solution with 1% total dissolved solids that has precipitates in it, you will:
  • most likely get a wildly incorrect result AND
  • get severely reprimanded by the technician in charge of the instrument PLUS
  • have to clean the instrument OR
  • pay for new consumables.
Speak to the lab manager and get their recommendations before proceeding.
  • asked a question related to Hydroxides
Question
1 answer
I need to find the electronic states of strontium hydroxide. while, the binding energy difference is small.
Relevant answer
Answer
How do come to the claim that the binding energy differences are small? O1s is quite well-separated from Sr3d or Sr3p.
Or are you interested in the valence band? In that case I suppose you will need a calculation in order to come up with a helpful interpretation, but in that case you might want to consider the usage of UPS instead of XPS, anyway.
  • asked a question related to Hydroxides
Question
5 answers
With due respect, I want to inquire about that how I can characterize some noble metal bonded in hydroxide form to some support. We can usually see with the XPS as there would be some binding energy difference but it's hard to differentiate between the chloride form of noble metal and hydroxide. We can see some difference at oxygen O1S in the form of metal-O bond (maybe) but the error range there is also very high. So is there any other possible characterization? Thanks!!!
Relevant answer
Answer
Yes XPES can be used or try to find out about something thermal methods which can be used
  • asked a question related to Hydroxides
Question
8 answers
My group start some research on the development of new biodegradable nanoparticles based zinc. We where intersted to observe that based powder X-ray diffraction analysis, it was almost no differences between the Zn oxide and the Zn hydroxide.
What is key to differentiate between both following your experiences based powder X-ray diffraction analysis!
Relevant answer
Answer
François Eya'ane Meva The XRD patterns for ZnO (zincite is the mineral form) and Zn(OH)2 (3 forms wülfingite (orthorhombic), ashoverite and sweetite (both tetragonal)). A simple Google search of the mineralogical databases should pick up the XRD patterns. For example, wülfingite, from the Handbook of Mineralogy. I attach the page.
In aqueous based systems, Zn(OH)x where x is nominally 2 will always be formed first and ZnO formed on calcination. This is true of many metal oxide 'nanomaterials' (e.g. TiO2) found in the literature.
  • asked a question related to Hydroxides
Question
7 answers
Hi everyone,
I wanna know if there is a robust method of measuring the iodine content in the cow milk. For plant samples usually the lab I been working uses Tetramethyl amonium hydroxide (TMAH) to extract iodine from plant samples and measurement is done by ICP-MS (Inductively Coupled Plasma – Mass Spectrometer). But we want to know how we can do it with milk.
Thanks.
Relevant answer
Answer
These publications also probably refer to analytics
  • asked a question related to Hydroxides
Question
3 answers
How is methanolic potassium hydroxide prepared?
Relevant answer
Answer
Dear Aws Maseer Nejres thank you for posting this interesting technical question. Potassium hydroxide (KOH) is quite soluble in simple alcohols like methanol or ethanol. Thus you can achieve different concentrations of methanolic KOH solution by dissolving KOH pellets in the required amount of methanol at room temperature (see e.g. the following link: http://cshprotocols.cshlp.org/content/2006/1/pdb.rec8238.full?text_only=true). The final concentration depends on what you plan to do with the solution. Some stirring or shaking might be required to achieve complete dissolution of the pellets. When handling methanolic potassium hydroxide solution always wear safety glasses. The solution must never come in contact with the eyes!
Good luck with your work and best wishes!
  • asked a question related to Hydroxides
Question
3 answers
We have tried synthesis of molybdenum hydroxide using MoCl5 aqueous water solution by simple electrodeposition on nickel foam as negative or working electrode. After deposition we got brown/black product on nickel foam. Since material is amorphous (checked XRD), we are not able to find its form (Mo(OH)2 or Mo(OH)4). please guide us and provide some references to investigate the deposited product. Thank you so much.
Relevant answer
Answer
Dear Umesh T. Nakate thanks for sharing this very interesting chemical prpblem with the RG community. Unfortunately it is not easy for me to give you a really qualified answer. In any case your electrodeposition reaction to form molybdenum hydroxides seems problematic to me. The first problem is, that MoCl5 is certainly not a suitable as precursor for this experiment. MoCl5 is known to be highly hygroscopic. It decomposes rapidly in contact with water under formation of oxychlorides and ill-defined hydrolysis products. Yet another problem is that molybdenum hydroxides are not just simple molecular compounds such as Mo(OH)5, Mo(OH)4, or Mo(OH)2. To the best of my knowledge, the compound Mo(OH)5 does not exist at all. Instead, they should be formulated as hydrated oxides. In the lower oxidation states (+2, +3), they can also form complicated cluster molecules. I think you should better skip the MoCl5 and try more stable and water-soluble precursors such as ammonium molybdate. For a potentially useful literature reference please have a look at the following article:
Electrodeposition of molybdenum oxides from weakly alkaline ammonia-molybdate electrolytes
(please see attached pdf file)
I hope this helps. Good luck with your work and best wishes, Frank Edelmann
  • asked a question related to Hydroxides
Question
8 answers
Does any one know a paper discussed the reversible reaction of aluminium hydroxide in sodium hydroxide solution? Send me suggested papers plz.
Relevant answer
Answer
Dear Ahmed S. Aadli attached please find a good overview of the Bayer process. Please note that when talking about "sodium aluminate" it is often not clearly distinguished between the compounds NaAlO2 and Na[Al(OH)4]. The latter is mostly present in solution and in the presence of excess NaOH. When you compare the two formulas you will see that the difference is just two H2O molecules.
  • asked a question related to Hydroxides
Question
2 answers
Hello all,
I'm having some difficulties with the issue. my system is combined of two layers stacked on top of each other (graphene and Ni(OH)2) using VESTA and the relaxed structure was achieved using VASP.
Rotation of the graphene layer will cause a rotation of its unit cell (for not breaking the symmetry in terms of periodic conditions in VASP) whereas the nickel hydroxide's unit cell will stay still (rotating graphene against nickel hydroxide).
My question is, how can I calculate a new unit cell from the basic unit cells of the two layers (one is rotated and the other is not) so the combined unit cell will give the right full structure of rotated layers in terms of periodic conditions? I'm guessing that using supercells could somehow fix the problem but it could be less accurate and more time consuming.
Thank you,
Eitan
Relevant answer
Answer
Dear Eitan Yohanan sorry to see that no experts have so far provided any qualified answers to your interesting technical question. We are synthetic inorganic chemists so that I'm absolutely to a specialist in this filed. However, the following instructive tutorial video might help answering your question (at least I hope so):
Plotting two structures in VESTA with rotation
I also came across a closely related technical question which has been asked earlier on RG. Unfortunately it has received only one (!) answer:
How to rotate 2d lattices in VESTA??
Nevertheless, I hope that this information is of some use for you and that experts in this area will provide more answers. Good luck with your work and please stay safe and healthy!
  • asked a question related to Hydroxides
Question
3 answers
our company uses potassium hydroxide as an electrlite in a hydrogen production electolysis cell, and we have a big stock of sodium hyroxide , can we use this sodium hydroxide as an alternative?
and if yes what parameters should be changed?
Relevant answer
Answer
Dear Abdulla Baltu thank you for posting this interesting technical question on RG. Yes, both sodium hydroxide and potassium hydroxide can be used equally in hydrogen production cells. For more information, please have a look e.g. at the following potentially useful link:
Hydrogen Production: Electrolysis
Good luck with your work!
  • asked a question related to Hydroxides
Question
4 answers
My sample is a zeolitic membrane which includes Al, Si, Na, O, ethylene glycol, TMAdaOH (N,N,N-Trimethyladamantan-1-aminium hydroxide), trimethyl amine, and alpha alumina as a substrate. TGA occurs in 20-600 centigrade degree and in air. I expect a small weight loss and I face with this increase.
Is it related to ethylene glycol boiling temp and intensity to react with ingredients ?
or Is it possible to face such a result?
Relevant answer
Answer
Thank for this response
  • asked a question related to Hydroxides
Question
10 answers
Hi,
Anyone know of any bases with boiling points < 100C that I can pretty easily boil off after a reaction? the lower the better and cannot contain any amines so ammonia is out
thanks in advance!
Relevant answer
Answer
Dear Nikhil Goel many thanks for sharing this interesting technical question with other RG members. I think that in order to give you a qualified answer it would be helpful if you could provide a few more details about your reaction system. For example, it would be useful to know why you cannot use ammonia or organic amines. The latter would of course be the volatile bases of choice. Moreover, you might want to specify if you are working in aqueous solution or in organic solvents. Please also clarify what the fundtion of the base in your reaction systems is supposed to be. In any case, the choice of volatile bases is clearly limited of you strictly exclude any amines. I should be glad to help in this case, but for that I really need a few more basic informations.
Good luck with your work and best wishes!
  • asked a question related to Hydroxides
Question
3 answers
Can you please send me JCPDS:
Cr2O3
Bi oxide
Co oxide
Bi hydroxide
Co hydroxide
Cr-CNT
Relevant answer
Answer
  • asked a question related to Hydroxides
Question
11 answers
I am synthesizing a material and thus far based on other scans I thought that it was a metal oxide at all stages but it has been suggested that the as-synthesized compound might be a metal hydroxide which after I anneal becomes a metal oxide. I am trying to determine a way to tell the difference between the two.
I have done the standard characterization on the as-synthesized compound (XRD, Raman, EDS, XPS) and trying to determine if something in one test will show up if it is a hydroxide and be absent for the metal oxide form.
I saw that Raman might have some OH bonding out near 3200-3500 cm-1 that might not appear in the metal oxide version. In previous Raman tests I did not attempt to scan out that far. If that is true will scanning the higher wave numbers help me determine the difference or is there another method that might be easier and more certain to differentiate between the two materials? Thanks for any help.
Relevant answer
Answer
Before annealing, you had hydroxides. They had to be watched by Raman at 3200-3500 cm-1. During annealing, usually all hydroxides decompose with the release of oxide and water vapor. If you have a 3200-3500 cm-1 band, then it should disappear with more prolonged heating. If it does not disappear and you are interested or interfered with by the presence of a small amount of hydroxyl groups, then you can investigate your composite in more detail.
  • asked a question related to Hydroxides
Question
6 answers
Can 'Ethoxide' ions generate when ethanol and sodium hydroxide solution were mixed and boiled over 160 celcius degree?
Relevant answer
Answer
Dear Tai Ju,
I just came across your very interesting technical question. To the best of my knowledge, delignification of wood is achived by action of sodium hdroxide alone. There is no need for ethoxide formation. Normally, sodium ethoxide (NaOC2H5) is prepared by reaction of ethanol with metallic sodium. A typical property of sodium ethoxide is that it is easily hydrolyzed in the presence of water. The hydrolysis reaction generates ethanol and NaOH. Thus in this reaction the quilibrium lies on the right side (ethanol + NaOH). This means that in the presence of water there will be no ethoxide ions present in your reaction mixture.
Good luck with your work and best wishes, Frank Edelmann
  • asked a question related to Hydroxides
Question
6 answers
I have 241 ppm EC50 values to F.oxysporum
Relevant answer
Answer
  • asked a question related to Hydroxides
Question
1 answer
I want to know the difference in kinetics of reaction would happen if MgO added in the form of carbonate and hydroxide during Iron ore sintering.
Relevant answer
Answer
Magnesium hydroxide at high temperature will be converted to MgO and it will react with an Iron oxide to create eutectic if temperature will be good enough for it. You have to check the MgO - Fe2O3 phase diagram and determine possible phases formation depends on the concentration of MgO
  • asked a question related to Hydroxides
Question
3 answers
I am going to use iron (ii) and (iii) solutions in my experiment and need to prevent the formation of iron hydroxide. As the precipitation might occur at high ph and the target ph for my experiment is 5, I want to know if there are any other methods (chemical) to prevent the formation of iron hydroxides?
Regards and thanks.
Relevant answer
Answer
Dear Mohammad,
My opinion is that if there is a slightly oxidizing environment in the solution, precipitation will occur, only the kinetics and mineralogical character of the product will change. If I remember correctly, ferrihydrite has a field of stability just around pH 5. At very low pH values below 2, the minerals of the jarosite group will precipitate and at pH values 2-4, with the addition of SO4-2, schwertmannite is stable. The safest way to prevent the precipitation of Fe oxyhydroxides will be to precipitate oxyhydroxides. Otherwise, it would be necessary to buffer the redox potential or chelate Fe 3+.
I would be interested in the stoichiometric gap as stated by @Mwanat Henock-Michel. Of course, transient FeII / FeIII compounds exist.
  • asked a question related to Hydroxides
Question
4 answers
Whether using a mixture of silicates and alkali solutions (e.g. Sodium/Potassium hydroxide and water glass) or an alkali solution on its own, how does its temperature affect the polymerization and setting time?
From my own experience I noticed the setting time to be significantly decreased when using a hot solution rather than a room temperature or cold solution.
Any input would be appreciated.
Relevant answer
Answer
Dear Ibrahim Al-Duais, you need to visualize the kinetics equations. Generally speaking, speed of reaction is a direct function of temperature, and time is the inverse. In the kinetics equations, temperature is sometimes inseen, but it is included in the constant 'k', which reflects the velocity. My Regards
  • asked a question related to Hydroxides
Question
3 answers
I could not find any specific name.
Relevant answer
Answer
Dear Roshanak Miraftab, polyacrylamides are used as floculant/coagulant. They may be : neutral, anionic, and cationic. Please see the following link. My Regards
  • asked a question related to Hydroxides
Question
1 answer
I am examining the materials for a silver discovery in Mexico in which a significant portion of the silver is refractory, hosted within argentiferous pyrolusite and aurorite. There is also the more easily accessible halides cerargyrite and bromargyrite, plus native silver. I interpret this to be a distal, lower temperature phase of an epithermal silver deposit environment.
Relevant answer
Answer
Dear Ben Whiting many thanks for your interesting technical question. Although I'm an inorganic chemist, I would certainly not call myself a proven expert in mining and mineralogy. From what I teach in my inorganic chemistry classes I would have spontaneously suggested cyanide leaching. Notwithstanding the high toxicity of alkaline metal cyanides, this is perhaps the most effective way of recovering silver form various ores and minerals. My initial guess is supported by the following potentially useful article which might help answering your question:
Mineralogy and silver distribution in argentiferous manganese ores from la encantada mines in Mexico
This article is freely available as public full text on RG. It's also advisable that you use the "Search" function of RG to find and access other relevant articles on the topic. Such search for terms like "silver recovery from ores" or similar. As you can see from the link cited below, this will provide you with numerous potentially useful articles which have been posted on this platform:
  • asked a question related to Hydroxides
Question
2 answers
I want to synthesize cobalt substutite alpha nickel hydroxide from Ni(II).(NO3)2 and Co(II).(NO3)2 precursor by increasing solution's pH.
During the precipitation reaction, anions in the solution are intercalated to Ni(OH)2 structure. To obtain a stable alpha nickel hydroxide, oxidation state of Co must be 3. But in the solution, cobalt's oxidation state 2.
Is it possible to synthesize Co+3 intercalated Ni(OH)2 from such a system.
Thanks in advance
Relevant answer
Answer
Dear Turan Ilhan thank you for your interesting technical question. It is known that in basic medium in the presence of oxygen (air) cobalt(II) can be oxidized to cobalt(III), whereas nickel remains divalent under these conditions. There are a few articles available in the chemical literature in which the intercalation of trivalent cobalt in nickel(II) hydroxide is reported. In this context please have a look at the following relevant articles:
Effect of Interlayer Co2+ on Structure and Charge Transfer in Ni/Fe Layered Double Hydroxides
Rechargeable Na/Ni batteries based on the Ni(OH)2/NiOOH redox couple with high energy density and good cycling performance
Co3O4/Ni(OH)2 composite mesoporous nanosheet networks as a promising electrode for supercapacitor applications
All three articles are freely available as public full texts.
  • asked a question related to Hydroxides
Question
4 answers
In microemulsion method (synthesis of metal oxide nanoparticles), why we use alkali hydroxide (NaOH aq or NH4OH aq solution) along with oil, surfactant and co-surfactant?
I appreciate the response.
Thank you.
Relevant answer
Answer
Solution alkalin aide a disperser les particules
  • asked a question related to Hydroxides
Question
5 answers
Hello,
is there a simple method for the wet activation of polystyrene using Potassium Hydroxide or Sodium Hydroxide? For activation, I intend the addition of Carboxylic group COOH to the surface of a common ELISA plate.
Thank you.
Relevant answer
Answer
Dear Luigi Marongiu thank you for your interesting technical question. The following article might help you in your analysis:
Immobilization Principles – Selecting the Surface for ELISA Assays
(see attached pdf file)
  • asked a question related to Hydroxides
Question
1 answer
I try to synthesis Zinc Hydroxide by using Zinc Nitrate and Sodium Hydroxide.
I know that the excess amount of Sodium Hydroxide may lead to form Zn(OH)4.
So, I stoichiometry synthesis Zinc Hydroxide by using 0.1 M Zinc Nitrate and 0.2 M Sodium Hydroxide following by this literature. (Equal volume of Zinc Nitrate and Sodium Hydroxide + Single addition of Sodium Hydroxide to Zinc Nitrate solution (pH after mixing is about 8.4), then washing by pump filtration technique, and drying overnight at 50 C in the oven.)
Turn out that the white precipitate that I synthesized is quite a pure phase of Zinc Oxide (Identified by XRD) which is completely different from this literature. So, I wonder what is the cause of this problem?
Thank in advance
"Zinc oxide and zinc hydroxide formation via aqueous precipitation: Effect of the preparation route and lysozyme addition"
Relevant answer
Answer
Dear Sirawit Hansethasuk thank you for the interesting question. It's is absolutely correct to avoid an excess of NaOH. However, pure Zn(OH)2 is normally prepared by re-dissolving the originally formed precipitate in NH3 solution and evaporating the ammonia in a desiccator in the presence of concentrated sulfuric acid. I think it can also achieved by concentrating the solution using a rotary evaporator. The detailed procedure is described in the following paper which is freely available as public full text on RG:
Synthesis of Zinc Hydroxide Nanocrystals and Application as a New Electrochemical Sensor for Determination of Selected Sympathomimetic Drugs
  • asked a question related to Hydroxides
Question
6 answers
Hello.
I am trying to measure trace metals contents of 48% Potassium Hydroxide with ICP-MS (Agilent 8900 QQQ).
What would be the ideal dilution factor to measure it without contaminating the tool?
Last time, I tried 10% dilution, and it ended up pausing the tool. I also used 1.5% HNO3 for acidification.
If anyone has experience with measuring KOH, please share your advice. Thank you!
Relevant answer
Answer
Jong Woon Park : Thanks for letting everyone know. It can be frustrating to see a question posed, solutions offered but no follow-up reported. Glad it all worked out for you.
  • asked a question related to Hydroxides
Question
1 answer
Hi all! I am trying to extract DBM from bovine and porcine bone, however removing the soft tissue has become time consuming. Doing some research, I found that dipping the bones in a 10% KOH (potassium hydroxide) solution would make it easier. However, I am concerned that this will affect my bone morphogenic protein.
Any help would be great!
Relevant answer
Answer
  • asked a question related to Hydroxides
Question
2 answers
Hello all,
I believe I've got (BiO)4OHCO3, but can't do employ my whole toolbox of techniques to confirm this because I can't find sufficient structural info on this phase. XRD pattern 00-038-0579 from ICDD's PDF-2 pointed me towards this phase- but our older database doesn't have structural info. I'd like to be able to run CrysTBox on the electron diffraction, and play with ball and stick models of this phase. If you have access to a reputable .cif, or can point me in the right direction, it would be very much appreciated :)
Relevant answer
Answer
Recently, I synthesized a (BiO)4CO3(OH)2 . And its PDF card number is 38-0579.
The attachment is the detailed PDF card information. I do hope that it will help you.
  • asked a question related to Hydroxides
Question
2 answers
I tried to synthesize pure alpha Ni(OH)2 by chemical precipitation ( Ni(NO3)2 + ammonia) following the ( ).
after the 4hours chemical precipitation reaction, I washed with distilled water with stirring and dried the results at roomtemrature, vaccum state.
However, the problem is my product contains nitrate ions. the xrd and raman spectra shows that my alpha Ni(OH)2 has nitrate intercalation.
Are there any possible tips for making pure alpha ni(OH)2 by chemical precipition or removing nitrate ions from the product?
(except for changing nickel nitrate to other nickel salts/ ammonia to KOH or Na(OH))
Relevant answer
Answer
I tried washed several times.. but I wash the powders much more, following your advices.
  • asked a question related to Hydroxides
Question
3 answers
Dear Researchers,
I am trying to optimize the metal complex and metal nitrate (Chloride and hydroxide) structure in the DFT with basic sets such as B3LYP/cc-pVDZ , B3LYP/LanL2DZ, CAM-B3LYP/cc-pVDZ , CAM-B3LYP/LanL2DZ using gaussian 9 software. But every time it stopped progress and shows link died. what would be wrong. how to solve this problem?
Relevant answer
Answer
The suggestions offered by Jürgen Weippert are all very good and represent the optimal approaches.
From your screengrabs it appears that you have SCF convergence issues with significant spin contamination. You may try using a restricted open-shell method. You can also try scf=xqc; however, you should check the results to ensure that you receive the desired state.
  • asked a question related to Hydroxides
Question
3 answers
I am trying to increase the yield for the reaction below. I did the column and I saw that the major side-product is the symmetric dimer formed by 4-bromobenzyl bromide. I imagine that NaH is hydrolyzed and the ions hydroxide (NaOH) eliminate the bromide by SN2, then this molecule does a second SN2 on 4-bromobenzyl bromide.
I ordered a new NaH, however, our glove box is not available at the moment. So, I am trying to find a solution to increase the yield of this reaction and achieve a final synthesis in gram scale.
Aiming to hinder the hydrolysis of NaH, I am purging N2 into the old flask every single time that I need to open the NaH flask, but I am not sure that this technique avoids the salt hydrolysis.
Thank you!
Relevant answer
Answer
Dear Gabriel Perli the quality of the used sodium hydride can certainly be crucial. Purging the flask containing the NaH certainly makes sense. Don't you have a Schlenk line which you could use instead of working in the dry-box? According to the original procedure, the entire reaction must be carried out under argon using anhydrous THF. Did you make sure that your THF was really dry? By the way, with 45% the yield reported by the authors isn't really very high.
My suggestion would be to use commercially available NaN(SiMe3)2 to deprotonate the starting alcohol. This reagent is not very air-sensitive. You yould also try elemental sodium to do the deprotonation. Then you see the end of the reaction when all the Na has dissolved.
  • asked a question related to Hydroxides
Question
16 answers
FYI, I have used XRD analytical technique for phase identification of a crystalline transition metal hydroxide. The analyzed material was finely grounded. I got some short and long peak for particular compound. How can I identify these peaks?
Relevant answer
Answer
Dear Masruck Alam,
I have attached one article and one book. I hope they would be useful.
  • asked a question related to Hydroxides
Question
3 answers
Hello forum,
I would like to know if TBA.OH is volatile in mixtures of acetonitrile or methanol. I want to analyze peptides that were previously dissolved in TBA.OH-conatining solution, but dried and re-dissolved in 0.1% FA. Would TBA.OH have been evaporated?
Thank you!
Relevant answer
Answer
Unfortunately, it won't be blown away. It is a common issue to deal with ion suppression effects at MS systems due to sticky nature but also it affects your separation efficiency which represents a stagnant phase at your column when using surfactants at your mobile phases. Bulk quantities at your final injection solvents can cause similar observation but in case of minor concentrations, I guess that it won't be a problem. It is always the best to remove surface-active molecules before MS injections for healthy chromatography and secure ionization since these molecules can interact with your peptides, the column, and also with your consumables resulting in low recoveries.
  • asked a question related to Hydroxides
Question
5 answers
Dear Colleages,
I want to know what is the hydroxide behavior in methanol? Will hydroxide remains as an ion like in water?
Relevant answer
Answer
Methanol can behave as a nucleophile which involves the electron pair donation by the oxygen atom to the atom other than hydrogen where as hydroxide anion is behaving as a electron donar to the atom hyrogen usually H+ . Both species behaves in similar way as the nucleophile but the way in which the electrons are donated is different.
  • asked a question related to Hydroxides
Question
1 answer
We recognized something interesting lately when dissolving iron(III)nitrate nonahydrate in pure alcohols: When dissolving litte iron(III)nitrate nonahydrate in pure alcohols, a solid forms, which is iron(III)hydroxide or iron(III)oxide. When adding more iron(III)nitrate nonahydrate, the solid dissolves and a clear liquid is obtained. The effect seems obvious to me: The hydrate water acts as additional solvent, and as water is a better solvent for any salts, the solubility is enhanced. Unfortunately this effect is superimposed by the oxidation of the alcohol, which makes it more complicated to investigate the phenomenon.
Is there any other solution known that has a similar behavior? A kind of "minimum solubility" of a salt?
Relevant answer
Answer
Seemingly, the solution of ferric nitrate in the alcohol/water solvent mixture may possibly first hydrolyse to form amorphous precipitate of iron(III) hydroxide, which is thermodynamically unstable, hence possibly slowly transforming to either α‐FeO(OH) or/and α‐Fe2O3, much depending on temperature.
  • asked a question related to Hydroxides
Question
4 answers
Can I use ethylene glycol as solvent for polyelectrolytes bearing carboxylic groups or hydroxide ions at room temperature? Concerning that ehtylene glycol can serve as either base or acid, will it react with carboxylic groups or hydroxide ions at room temperature? Thank you! 
Relevant answer
Answer
Dry ethylene glycol is known to dissolve some organic acids, such as acetic acid, formic acid, or oxalic acid; cf.: H.J. Baars, A.N.R. Bos, J. Kars, "Process for separating ethylene glycol", US Patent 6,525,229 B2, Feb. 25, 2003.
  • asked a question related to Hydroxides
Question
1 answer
My lab has just installed a new IC from thermo. I‘ve had no trouble at all finding other anions of intrest, other than iodide, which is pretty important to our work. I’m using hydroxide as the eluent, a 500 uL injection loop, and an AS28 column. I understand the case might be that I need to look into another column, but hoping anyone has been able to identify iodide with this column?
Relevant answer
Answer
The hydrophobicity of the Thermo Scientific Dionex IonPac AS28 column is rated "medium-high." It means that polarizable anions will show a more substantial - adsorptive governed - retention time. A helpful hint is the late elution of bromide and nitrate (both standard anions with quite some adsorptive interaction with the resin). The resin was predominantly developed for the trace level anion determination, and the determination of weakly retained monovalent organic acids.
I think the easiest and fastest way to help is to use the free "Appslab" library and the "Virtual column" chromatography simulation tool, which is embedded. I added the link to Appslab below. Just search for iodide and click your matrix. The significant benefit of Virtual Column": Its simulations are based on real data, so that the results are very close to the experimental findings.
I am crossing my fingers! In case of any questions, please let me know.
Good luck with your research
Detlef.
  • asked a question related to Hydroxides
Question
6 answers
Lime is soluble in water to a small extent forming calcium hydroxide. What methods are available to increase the concentrations of calcium ions and hydroxide ions in aqueous solution?
Relevant answer
Answer
The solubility of calcium hydroxide is considerably higher in glycerol than in water. It also increases for glycerol―water solutions.
  • asked a question related to Hydroxides
Question
5 answers
Dear friends,
Why aluminium hydroxide reaction with hydrochloric acid AR give yellow solution.
we required clear solution.
Please suggest .
Relevant answer
Answer
I coincide with Frank T. Edelmann . I work with several Aluminum-containing reagents and all of them have the iron salt as a impurity, thus, the yellow color may result from such impurity.
All the best
  • asked a question related to Hydroxides
Question
4 answers
What is the photocatalytic mechanism of hydroxide based materials? Example : Mg(OH)₂, Ti(OH)₂, Fe(OH)₂,Ca(OH)₂ . How to write equation form of mechanism?
Relevant answer
Isam Eldin Hussein Elgailani @ Thank you sir, these article are clarify my question.
  • asked a question related to Hydroxides
Question
3 answers
I am looking for either a temperature based equation or a graph of Cp versus T.
thanks
Relevant answer
Answer
Zinc hydroxide has specific heat capacity of 81.2 J/mol K
Source: My mobile handset. Thank you.
  • asked a question related to Hydroxides
Question
3 answers
i. Arsenic hydroxide
ii. Selenium hydroxide
iii. Aluminium hydroxide
iv. Chromium hydroxide
v. Copper hydroxide
vi. Iron hydroxide
vii. Lead hydroxide
viii. Mercury hydroxide
References should be sent to me including:
a. Author(s)
b. Year
c. Title
d. Edition
e. Volume
f. Location
g. Publisher
Relevant answer
Answer
Arsenic hydroxide - Heat capacity, C p = 85.0 ± 10.0 J/(mol K)
Reference:
Erwan Perfetti, Gleb S. Pokrovski, Karine Ballerat-Busserolles, Vladimir Majer, François Gibert, Densities and heat capacities of aqueous arsenious and arsenic acid solutions to 350°C and 300bar, and revised thermodynamic properties of As(OH)3∘(aq), AsO(OH)3∘(aq) and iron sulfarsenide minerals, Geochimica et Cosmochimica Acta, Volume 72, Issue 3, 2008, Pages 713-731
  • asked a question related to Hydroxides
Question
6 answers
In the synthesis of geopolymer cement, it is suggested to prepare the hydroxide solution 24 hrs before using it in the mixture so that it cools down. How the setting period is significant? If I used the solution 72 hrs after preparation, does that affect its reactivity?
Please attach any reference that discusses the reactivity of NaOH solution with time.
Relevant answer
Answer
Yes, you can use sodium hydroxide after 72 hours of preparation. However, you have to ensure that where the sodium hydroxide is stored is well sealed as sodium hydroxide is hygroscopic and can absorb moisture from the environment.
  • asked a question related to Hydroxides
Question
4 answers
I have screened 2 fungal strains isolated from serpentine soil for the Cu tolerance (0 ppm - 2000 ppm). At the very first copper in the 1600ppm and 2000ppm (incooperated into Potato Dextrose Agar) were precipitated during the adjusting of pH of the media. But i continued the culturing of fungi in those concentrations also. After 12 days the results was their growth has decreased with the concentraion increment. But next time i added a same volume of EDTA of concentration 30 ppm to each copper concentration + PDA to avoid the precipitation of copper hydroxide. But after 12days the result was confusing. The growth of the fungi has increased with the increment of copper concentration. Can anyone please help me to solve this confusion.
Relevant answer
Answer
Dr. Norman, Dr. Asemoloye, Dr. Macro thank you very much for your answers. Actually i used a EDTA without copper as a negative control. In that one the fungal strain didn't grow showing the inhibitory effect of EDTA. But my problem is as i used same amount of EDTA in each 400, 800, 1000, 1200 ppm of Cu + PDA medium how the fungal growth increased with the Cu concenttation.
  • asked a question related to Hydroxides
Question
4 answers
Chloride salts of following organic bases are commercially available. How can I get their anhydrous hydroxide form?
N,N-dimethylamine, N,N,N-trimethylamine, Guanidine, N-mrthylguanidine and N,N-dimethylguanidine
  • asked a question related to Hydroxides
Question
7 answers
Hi,
a friend of mine found the following question in preparation tests for medicine:
How much water do you have to add to 1 ml of solution with pH 8 to reach pH 5?
I assume they want simply calculation pH = -log [H+]
But in reality, what would be the pH of for example NaOH with concentration e.g. 10^-9 M? In such case the concentration of OH- originating from the hydroxide would be 10^-9 M, so at first sight, one could say the pH would be pH = 14 - pOH = 14 - (-log(10^-9)) = 14 - 9 = 5.
But of course the hydroxide will not have acidic solution, because the water dissociates. Is there a (simple) way to calculate the pH?
Just to make sure - that question is nonsense, right?
Thank you
Relevant answer
Answer
Note that close to neutral pH (7) we can not neglect [H3O+] compared to [OH-].
Sodium molar balance writes: CNaOH = [Na+] + [NaOH], where CNaOH is the nominal molar concentration of NaOH in aq. sol. (formality, to be precise). Because NaOH is a strong base, it should be highly dissociated in aq. sol., so that [NaOH] << CNaOH. Hence: [Na+] ≈ CNaOH. Charge balance writes: [Na+] + [H3O+] = [OH-]. Then we shall have: CNaOH = [OH-] - [H3O+] = (Kw/[H3O+]) - [H3O+], or [H3O+]2 + CNaOH·[H3O+] = Kw, where Kw = 1.0·10-14 M2 is the autodissociation constant of water. Therefore, [H3O+]/M = - (½)(CNaOH/M) + √{{Kw + (¼)(CNaOH)2}/M2}, and:
pH = - log10{[H3O+]/M} = - log10{- (½)(CNaOH/M) + √{{Kw + (¼)(CNaOH)2}/M2}}
For CNaOH = 10-9 M; last equation yields: pH = - log10(½) - log10(10-7) - log10{-10-2 + √{4.0·10-4/10-4 + 10-4}} = 7.002
  • asked a question related to Hydroxides
Question
3 answers
I have been looking into MSDS of KOH of 0.1 M, and it says use proper ventilation area while working. But in my lab, we don't have fume hood to work with. And I am not able to find any safety sheet on 0.001 M KOH solution. I would also like to know about any possible health effects of this.
Relevant answer
Answer
Only concentrated KOH is dangerous (Caustic soda). But solutions of 10 - 15 % (that is around 2 mol/l) are medically used for topical application.
I can find safety data for a KOH solution of 0.1 M at a Sigma-Aldrich site
NO STATEMENT for special ventilation is given for 0.1 M KOH
But for 0.001 M, their could be no harm at all (except do not swallow ..). No need for special ventialtion or fume hood.
  • asked a question related to Hydroxides
Question
4 answers
What are the essentials for carrying out a reaction between lead nitrate and sodium hydroxide?
Relevant answer
Answer
Lead(II) nitrate is an inorganic compound with the chemical formula Pb(NO3)2. It commonly occurs as a colourless crystal or white powder,unlike most other lead(II) salts, is soluble in water. Lead(II) nitrate can be obtained by reaction of lead(II) oxide with nitric acid ......When concentrated sodium hydroxide solution is added to a nitrate solution, basic nitrates may be.....Simple Pb(OH)2 is not formed up to at least pH12. For more details consult https://en.wikipedia.org --wiki
  • asked a question related to Hydroxides
Question
1 answer
I am cunducting an experiment in which t have successfully removed phosphorus in the form of hydroxyapatite. My experimental results showed that the reaction might be diffusion contrlolled("Shrinking core model" in particular) and modelling also confirms the result.
I will be highly grateful if anyone kindly provide me with any relevant information.
Thank you in advance.
Relevant answer
Answer
I suggest tyat you look at the papers describing formation of nanoclusters during precipitation of CaCO3
  • asked a question related to Hydroxides
Question
3 answers
Hello All,
Is there any recommendation to modify chitosan by hydrazinium-hydroxide to increase amino groups? Thank you.
  • asked a question related to Hydroxides
Question
3 answers
Hello,
I am researching electrochemistry and supercapacitors seem very interesting to me, but poorly I don’t find very much research on really high-capacitance metal-oxide free ones. So I wanted to ask what were the highest capacitance values ever achieved in a metal oxide-and hydroxide free type? I am searching for 500F/g and ascending.
thanks a lot
Relevant answer
Answer
Capacitance depends on various factors including morphology, surface area, pore volume and size, electrolyte, potential applied, active material loading. In case of metal oxides, it also depends on work function of MO, crystal structure, lattice orientation, defects/vacancies, surface chemistry etc. See more details in the following paper
"Supercapacitor performance evaluation"
Unfortunately, there is no standard protocol to report electrochemical performance in Supercapacitors.
  • asked a question related to Hydroxides
Question
4 answers
I am trying to make 0.5M zincate solution in order to measure zincate crossover of my membrane. Basically, I need to dissolve zinc hydroxide in KOH, 7M solution to get it. However, I do not have zinc hydroxide in the lab. I was wondering if I dissolve zinc chloride or zinc sulfate in KOH, 7M. will I get zincate solution suitable for my test? or presence of chloride ot sulfate ions in the solution may intervene in the process? Thanks
Relevant answer
Answer
I really Appreciate your answer. Thanks Fuhui Cui