Science topic
Acids - Science topic
Acids are chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. (Grant & Hackh's Chemical Dictionary, 5th ed)
Questions related to Acids
I am synthesizing choline geranate, an ionic liquid.
Before synthesis, I need to recrystallize geranic acid (85%), but I am having difficulty understanding the recrystallization method.
According to the research paper, recrystallization should be performed at -80°C.
To achieve this, I set up a water bath with acetone and dry ice to maintain -80°C and prepared a saturated solution of geranic acid in acetone at a 7:3 ratio. This allowed me to observe a solid precipitate forming through recrystallization.
However, I am unsure how to remove the acetone and isomers in this process. When I tried using filter paper for filtration, the geranic acid quickly dissolved.
Since this is my first time conducting this experiment, I would appreciate any advice on how to proceed with this step.
Dear RG community,
I am looking to use magnetic colloids which are to be further dispersed in a polymer. To avoid agglomeration, I want to functionalize them using Oelic acid. I would appreciate if someone can point towards the exact procedure or a correct way of doing so. Also what purity grade oelic acid one needs to use (technical, culture, analytical etc.)
Thank you in advance
Bonjour Mme Lemosquet,
Je suis salarié dans l'entreprise INNOVAL et en charge du support technique RUMINAL auprès des conseillers d'élevage.
J'ai des difficultés à comprendre le fonctionnement de RUMINAL concernant l'évaluation des apports en acides aminés digestibles et à savoir comment manipuler les données "aliments" et les indicateurs fournis par le logiciel.
Je souhaiterais avoir des informations de la part de la ou des personnes responsables du mode de calcul.
Pouvez-vous me dire qui est le.la référent.e INRAE sur ce sujet ? Mon seul contact RUMINAL est Pierre Nozière. Dois-je le contacter ou une autre personne (vous?) peut m'aider ?
Cordialement,
How are ester bonds hydrolyzed in a polylactic acid molecule?
What are the specific steps for the preparation of polylactic acid by the two-step method?
What role do terminal carboxyl groups play in the degradation of polylactic acid?
Is it possible to determine total sulphur in plant material from microwave acid digestion with nitric acid?
Thank you.
What are the characteristics of the method for preparing high molecular weight polylactic acid by reaction extrusion?
For failure analysis, sometimes parts received contains fully rusted fracture surface and surrounding areas. Is there an acid solution out there for soaking the parts or spraying solution to the corroded area to remove the corrosion products and obtain a clean surface for analysis?
We analyzed WSC to used method of phenol-sulfuric acid by spectrophotometer, and we calculated calibration curve. what do I need do next step? I don't know what I need do after this calculation. please help me
I am working on extracting tartaric acid from archaeological samples. So far, I’ve tried using MeOH/DCM and BF3/Butanol/Cyclohexane, but was not successful for real samples. I was able to get tartaric acid peak in GC-MS for fresh wine. Does anyone have suggestions on how to improve the extraction efficiency or alternative methods that might work better?
I recently performed a gas chromatography-mass spectrometry (GC-MS) analysis on a propolis sample and identified allocholic acid among its constituents. Considering that allocholic acid is a secondary bile acid primarily associated with mammals, I was intrigued by its detection in a product sourced from bees. Is the occurrence of allocholic acid in propolis a common phenomenon, or might this finding be influenced by specific botanical sources or distinct regional variations in propolis composition? Additionally, could there be potential interactions with the bees' microbiome or enzymatic activities that might account for this observation? I would greatly appreciate any insights or references to similar reports.
As I claimed in my adsorption mechanism they adsorbed into the pore of MIl-101(Cr). How can I do it?
Hi scientists,
The color of my samples in Phenol-Sulfuric Acid method turns into a bluish-greenish color after I add the sulfuric acid (5:1) to the sample containing phenol 5% (1:1).
This have happened several times, can anyone help me?
Problem: reaction mixture has a black tar like texture so that it is not forming layers while doing workup with DCM and water+sodium carbonate anhydrous.
I have seen in literature people using buffers such as PBS with pH 7.4, and dilute it with acid or base to create lower pHs like 2, 3,4 or higher pHs , will it still be called a buffer once buffering capacity is lost?
How can I prepare 3,5-dinitrosalicylic acid (DNSA) reagent used in Alpha Amylase Inhibition Assay? Any reference paper is available?
Hello everyone. I have been struggling a lot with my western blots. I am treating my cells with short chain fatty acids and then extracting my proteins using RIPA/protease inhibitor lysis buffer. after that I am qualifying my proteins using Lowry assay, I am trying my best to avoid bubbles and to get accurate results.
the proteins I am trying to detect are vimentin and beta catenin. Migration assays and real time PCRs as well as previous results strongly demonstrate that there will be down-regulation of these proteins in response to the treatment.
when it comes to western I am struggling with equal loading since actin bands are looking inconsistent (especially in the control I am getting thin bands and with other samples as well). and the westerns have not been giving the expected results. I have repeated the westerns many times and I am still struggling... Can someone please help and suggest if there might be anything wrong with the quantification, cell seeding (working on SKOV and PA-1) or loading (although I doubt since previous westerns have given really good results).
I use BG11 to cultivate PCC.6803, and bubble with 3%-4% CO2.
20mM Tris-Hcl(pH8.0) were used to buffering the culture pH.
But after clutivate 2 days, when I test the pH of the culture, the pH always be around 6.5, and it's always acidic.
I guess the reason is the bubbling CO2, to make the culture acidic.
So what can I do to maintain the pH around 7.5-8?
Any suggestion would be highly appreciated.
Hello
What should be done to separate and identify organic acids in HPC when their RetTime is the same?Like oxalic acid with Propanoic Acid.or acids that have a very close RetTime.
Hi, I'm learning about methods to separate acids and organic matter and trying to establish an experiment integrating DD and AR. While I was doing my research few questions popped in my head:
1. On what scale can these respective technologies can be conducted? If I am to separate H2SO4 from H2SO4-Glucose Mix on which rate can I extract it? 10L/day, 100L/day 100m3/ day? The pump specifications may change due to this so I'm asking this question.
2. What are some common practices in the industry to handle strong acids of different concentrations? H2SO4 is strongly acidic, and the piping/tubing, and the machines responsible for diffusion dialysis and acid retardation should also be able to withstand strong acids right? PTFE and 904L steel comes to mind are there other materials available to withstand corrosion?
3. What are some common resins used for Acid retardation? Seems like there is a wide array of materials and different companies depending on the region.
Thank you so much for taking your time to read this questions and answering them :)
I'm exploring the development of a material that dissolves in basic pH environments but remains stable in acidic pH conditions. I'd like to start a discussion on the feasibility of this concept, potential materials that could fit these criteria, and the challenges we might face in achieving this balance. Any insights or suggestions?
We are preparing one solution of different organic acids, but our target ph is 4.5, but due to acid nature of solution its pH ranging below 1.2-1.5. We tried to balance the ph with KOH, NaOH but both are not suitable, its start precipitating. Is there any other alternate and plants safe chemicals are thare to balance it ..?
Suppose edema or high urea than what to do
I am working with amolecule which only soluble in acid or bases.
Penconazole
1. CGA 132465
2. CGA 190503
3. CGA 127841
Fluopyram
1. AE C656948-benzamide
2. AE C656948-pyridyl-acetic acid
3. AE C656948-carboxylic acid
I have searched on sigma aldrich as well as on dr. erhenstofer site but i did not find any results.
"What is the best pH for the preparation of a Schiff base from guanine and salicylaldehyde?"
And what is the mechanism in acidic and basic medium?
What's your suggestion for converting a heavy organic alcohol to its corresponding acid (via oxidation or dehydrogenation)?
Your industrial experience is appreciated.
and chloroformate. But it takes 10 days to compete the reaction. How can I shorten the time of the reaction?
I want to replicate the third step, but there seems to be no reaction in an alkaline environment. However, sodium hydroxide is used in the literature. Should I switch to an acidic environment
I have synthesized CaFeO3 three times using metal nitrates through sol-gel method but each time XRD analysis show that its peaks match with Ca2Fe2O5. Metal to acid ratio is 1:1.38. I've also tried adding ethylene glycol.
by which acid can we replace sulfamic acid to eliminate nitrite in a soil extract to determine the nitrate content by the DEVARDA method
i was preparing gelmA by already reported method. but im unabke to seperate side product methacrylic acid and unreacted methacrylic anhydride. we donot have dialysing membrane facility nor we have lyophilization technique. kindly tell there alternatives
I have taken around 100 mg of sample for digestion and final volume was 50 ml. But the acid concentration was too high in the sample so I had to dilute it again. I have taken 1 ml from the 50 ml solution and diluted it again to 50 ml. What will be my final dilution factor?
Hi all,
I'm working on some acid-mediated sol-gel syntheses to make metal oxides. I have a few formulations working using only acetic acid, and metal-alkoxide precursors. However for some formulations, I need a pH lower than acetic acid can achieve alone and I'm unsure what alternatives to look for
Using fluorinated analogs of acetic (trifluoroacetic) did successfully work to lower the pH of the sol-gel and form smaller clusters, but also formed metal-fluoride species in the final products
Using formic acid appeared to work, but caused precipitation later on (too polar).
So basically I'm looking for an organic or mostly-organic acid to mix into acetic acid, to lower the solution pH without forming metal salts as a byproduct. Any suggestions?
Use of thioglycolic acid as a stabiliser during the synthesis of nanoparticles
While the purpose of adding acid types into the PVA plasticizer when making gel electrolytes in supercapacitors is for conductivity, what are the other purposes? So why do we add acid? Why do we add specifically sulfuric and phosphoric acid? Or KOH is added, is there a review or article explaining their purpose? I would appreciate it if you could share what you know, if you have any. There are interpretations of the electrochemical results when different gels are used. But I would like an article or rewiev on why they are used. In other words, it's a bit like the history of gel electrolytes, etc...
I am trying to detect organic acids on my waters LC, which is equipped with a W410 refractor index detector. I am using a Aminex HPX-87H Column which is supposed to work to separate organic acids. I’m not sure if I’m missing something in my method settings but I am not detecting anything at all. If anyone has any insight that would be greatly appreciated
I have synthesized GO using a modified Hummer's method as follows: 0.125 g of graphite fine powder and 0.125 g of sodium nitrate were mixed followed by the addition of 5.75 ml of concentrated sulphuric acid under constant stirring for 10 min (in an ice bath). After that, 0.775 g of potassium permanganate was added gradually to the mixture (in an ice bath) and stirred for 10 min - the mixture color turned to dark green. Then, the reaction mixture was transferred to a pre-heated oil bath and stirred at 35 °C for 1 h. The obtained mixture was diluted by the addition of 10 ml of DI water, then heated up to 90 °C for 30 min. Again 25 ml of DI water was added. Last, 1 ml H2O2 was added to terminate the reaction -the mixture turned to earthy yellow. I washed the product with distilled water and dried it at oven 60 °C for 24 h -the resulting product is a little bit sticky black solid.
I want to synthesis sodium polyacrylate 40% solution in water in order to use it as dispersing agent for CaCO3. i have acrylic acid, NaOH and potassium persulfate as initiator. any one can help me in the order of adding materials to the flask, reaction temperature, time and if it is possible to do this reaction at room temperature after initiators are turning into free radicals at 60°C?
I would like to double hydrolysis of an agricultural residue using sulphuric acid. The problem lies in the preparation of solvent dilution. Thank you
At our lab we are trying to develop new dyes for different applications, and we need information about the stomach acidity of Galleria mellonella model.
My objective is to find the binding affinity of divalent metal ions with polyacrylic acid (PAA) by Isothermal Titration Calorimetry. In this experiment, I need to prepare 2mM of PAA. The 2mM should be in monomer concentration terms. So, How do I calculate how much mass of polyacrylic acid do I need to measure if the average molecular weight(Mw) of choosen polyacrylic acid is 12000. If someone knows, please tell me in detail with mass calculation strategies.
My objective is to find the binding affinity of divalent metal ions with polyacrylic acid (PAA) by Isothermal Titration Calorimetry. In this experiment, I need to prepare 2mM of PAA. The 2mM should be in monomer concentration terms. So, How do I calculate how much mass of polyacrylic acid do I need to measure if the average molecular weight(Mw) of choosen polyacrylic acid is 12000. If someone knows, please tell me in detail with mass calculation strategies.
Hello,
I am performing esterification reactions between fatty acids and alcohols, in presence of methanesulfonic acid and H3PO2 as catalysts. At the end of the reaction, to reach the acid index I want, as well to neutralize the catalysts, I use NaOH, 30 % solution. At the end of the reaction, I perform filtration by using some powders. What I observed is that after a while the acid index increases, this being un inconvenient, because it should be in a certain range. I believe that this might be the effect of an reversible reaction, which means that the catalysts are still active.
What can I use at the end of the synthesis for the neutralization of the catalysts to be sure that the reversible reaction won't take place? or may be there are some composite able to adsorb them?
thank you in advance,
Elena
Hello, I am currently conducting my Bachelor on a organic synthesis. Here, I first form an acid chloride by the addition of thionyl chloride and Dimethylformamide (which together form the Vilsmeier-Haack reagent) to my starting product (4-hydroxyphenylacetic acid) at room temperature. After, I add Triethylamine (a proton scavenger) and a dimethylamine HCl salt, the latter of which should react with the acid chloride in a amidation reaction. However, upon addition of the DMA.HCl nothing seems to occur and a IR-spec analysis of the final product shows a molecule reminiscent of polyethylene terephthalate (PET). This finding makes me think that there might be a polymerization reaction going on in which the acid chloride reacts with the hydroxy group of 4-hydroxyphenylacetic acid. This would also be able to explain as to why the DMA.HCl would not react in the mixture as all the acid chlorides would have polymerized before the amidation could occur.
Hello everyone, recently I am trying to synthesize a dipeptide with a Coumarin derivative of Tryptophan, and the problem is it doesn't contribute in reaction at all.
Tryptophan itself in the same condition participated in reaction but the coumarin derivative does not contribute.
I have tried different agents such as TBTU and DIC/HOBt with PH=8
I tried activating the acid with N-hydroxysuccinimide but it didn't help.
What other parameters I can try or change?
Hello, everybody.
I am looking to add a DNAse treatment step to my bacterial lysis (gram-negative) procedure for crude enzyme extraction because my lysate always ends up being too viscous. We only have Zymo Research DNAse I in the lab and its information sheet says not to "avoid phosphate buffer and calcium chelators". However, I am using a chemical lysis procedure using Promega Cell Culture Lysis Reagent (following their bacterial lysis protocol) since we do not have a sonicator available. According to their information sheet, CCLR has 25mM Tris-phosphate (pH 7.8) and 2mM 1,2-diaminocyclohexane-N,N,N´,N´-tetraacetic acid. Does anyone know if adding DNAse I to my lysate will still work?
I am not sure of the composition of Zymo's DNA digestion buffer, but I was thinking of supplementing divalent ions to the lysate to counter the 2mM chelating agent in the lysis buffer. However, I am not too sure how to circumvent the phosphate problem. I am not sure how phosphate affects DNAse activity exactly. On the other hand, Thermofisher has a protocol for removing DNA from protein extracts (extracted using lysis reagent in phosphate buffer) using DNAse I. Will the phosphate component of my buffer significantly affect the activity of the DNAse?
Any insight on this matter will be greatly appreciated. Tips on how to solve the viscosity problem altogether are also greatly appreciated.
Thanks
I have synthesized a sensor, which has sulphonic acid grp (-SO3H) and Boronic acid as well in it. And has a Molar mass of around 899 and also has an amide bond in it.. I am using Reverse phase HPLC to purify using ACN and Water(0.1%) as mobile phase. As I separate the compounds of one peak, the next very day it is splitting into two peaks in the chromatogram. Is TFA creating a problem? I could not figure it out. Should I need to use a buffer as an additive instead of TFA? Which buffer and how much is good for use? Could you please suggest?
I'm using the vanillin-sulphuric acid method to cuantify saponins but the colour that I observe is yellow instead of red-purple.
The method I follow from the literature is:
- 1 ml of sample extract + 0.25 ml 8% (v/v) vanillin in methanol + 2.5 ml 72% H2SO4
- Incubate mixture in 70ºC water bath for 15 min and then in ice for 5 min.
- Read absorbance at 560 nm.
Any sugestion or solution for this problem?
Thanks!
Hi,
I am getting elevated results in my starch analysis. It is about 2-3 % higher than usual. We have not changed anything. We are getting the same results over and over. I have checked the 0.309M HCL, and it is perfect. Does anyone know why it sometimes reads higher?
When we put it into a boiling shaking water bath, we agitate it constantly. I have even tried not agitating it and I get the same values.
I have made the acid up a few times and checked it and it is fine.
The water baths temp is correct.
We filter it using 5-8um filter paper as we have in the past.
Thank you.
Kind regards,
Rob
Does dissolving the scaffolds in acid work to quantify that using spectrophotometer? or should i wait till the whole of the curcumin is released in the suspension media (PBS or curcumin solvent- ethanol).
[(CH3)3NCH2CH2OH]+Cl- + CH3CHCOOH + HOC(CH2CO2H)2 -> ???
2-Hydroxy-N,N,N-trimethylethanaminium chloride + 2-hydroxypropanoic acid + 2-hydroxypropane-1,2,3-tricarboxylic acid -> ???
Hello,
I am generating brain organoids. Some media require vitamin B27 +A, but we currently have vitamin B27 minus A vitamin. How bad will it be if we use B27 minus A instead of B27 + vitamin A? We also have retinoic acid. Would it be appropriate if B27 minus A were added (and how much)?
Hi, I have to prepare the YCFA culture broth and do a bacterial growth test with each of the bile acids, however I am unable to dissolve the acids (lithocholic and ursodeoxycholic), any suggestions on how I could dissolve them? Also, would these acids degrade if I autoclave them?
I would greatly appreciate your advice
Please provide information on where I can purchase a 150 kDa, 500 kDa, 1000 KDa and 5000 KDa molecular weight cutoff membrane? for separation of ferulic acid (194 mwt) form mixtue of sample. where almost other molecular wt cut of is ranginng form 100 - 150.
What are the differences between 50 mM glycine-hydrochloric acid buffer (pH 3) and 100 mM glycine-hydrochloric acid buffer (pH 3), especially regarding osmotic pressure? Why do they have the same pH value but different glycine concentrations.If I need to use it to wash cell , which concentration of glycine buffer is closer to isotonic, thereby ensuring cell survival?
I would like to calculate the volume from certain concentration,
people used 100 µL of 2 g/L solution then add to 100 ml acidic solution. how much volume should be if I will use concentration of 40 mg/L which will be added to 25 ml solution? Please write the calculations in details. Thanks
I am facing a reproducibility issue. I am measuring the specific capacitance for my sample (carbide based). I am getting pseudocapacitive behavior in CV curves. The first time while measuring GCD i am getting around 100 F/g at 1 A/g current density, but when i try to repeat the same i am not getting the same value. Moreover the GCD curve is not triangular shape.
Electrolyte used is 1M Sulphuric acid
Mass loading is from 1.3 to 1.8 mg/cm2
Potential window is from -0.1 V to 0.4 V
I used TBAPF6 electrolyte for CV study but it generated anion of my compound. Please suggest me which electrolyte would be suitable for cyclic voltametric study of mild acidic organic compounds?
How much quantity of sulphuric acid is required for acid hydrolysis of chemically purified cellulose powder to produce crystalline nanocellulose?
PGA solvents are toxic and I need a better approach to create films with this polymer.
In advance, Thank you for you time and consideration.
Respected Researchers
Kindly explain the below mentioned formula for the calculation of TAN. I am not able to understand 4 in this formula.
Thanks in advance
45ml of 55% w/v sulphuric acid was taken. To hydrolyze 1gram of bleached mango wood cellulose. On addition of this powder to the sulphuric acid at 45°C , the mixture turned dark black! Whereas other article suggest that nanocellulose suspension should have been whitish? Why is it so?
Preparation of EDTA-
Citric acid solution in water.
I have come across a suggestion to use HF and HNO3 mixture. But exact ratio is not clarified. What should be the exact ratio of these two acids to smoothly pickle Ni sheets? Any impurity in form of oxides must be absent before electrodeposition.
Hello, I have nylon fabric dyed with Acid dye. I need to prove for part of my project, is it possible or not possible, the reaction between dye molecules absorbed in nylon fabric with water molecules when the fabric is immersed in water. I hope someone helps me to find the best answer to this question.
Hello everyone,
I need to use a final concentration of 90ng/uL of BSU polymerase in a final volume of 50uL. The NEB BSU polymerase specification sheet indicates 5ng/uL as the stock concentration. How do I convert units/uL to ng/uL knowing that one unit is defined as the amount of enzyme that incorporates 10 nmol of dNTP into acid insoluble material in 30 minutes at 37°C.
I am not 100% sure but I know that:
Specific activity (units/ng) = 5 U/μl / 10 nmol
To convert nmol to ng, we need to know the molecular weight of dNTP. Assuming an average molecular weight of 330 g/mol for a single nucleotide, we can calculate the specific activity in units/ng as follows:
Specific activity (units/ng) = 5 U/μl / (10 nmol x 330 g/mol)
and... if this is correct... then what?
Thanks a lot :)
1. Oleic acid
Oleic acid is classified in a long chain acid. Should we keep in the acid storage cabinet? or keep in the general storage cabinet? which one would like to recommend?
2. Triethylamine
Triethylamine is classified in both "flammable" and "base". So, should we keep in the flammable cabinet? or keep in the base storage cabinet? which one would like to recommend?
would you give me an answer with reference articles?
What are the possible ways of rectifying a lack of fit test showing up as significant. Context: Optimization of lignocellulosic biomass acid hydrolysis (dilute acid) mediated by nanoparticles
Which steps, materials, temperature or stirring contain this process? Is there any publish or book? I want to materials make up only sulphuric acid and pyrrole monomer. Because my materials are unsufficient.. Thank you for your attention.
I intend to modify a media, to better access de potential of bacteria (Pseudomonas and Bacillus) to produce organic acids in solid medium.
Hi!
I have a bacterial strain that changes the pH of the broth making it acidic. I want to get a knock-out mutant that is unable to lower the pH.
Since I'm using transposon mutagenesis without finding the transformant I want, I was considering to analyse the annotated reference genome to find the genes involved.
Honestly, I don't know where to start from.
I mean: should I look into the methabolic pathway using Kegg database or there are better ways to dig into the genome? Shoul I look for genes involved in the production of acidic compunds? How?
Any advice is appreciated.
Thanks!