Science topics: Chemistry
Science topic
Chemistry - Science topic
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds.
Questions related to Chemistry
According to "Handbook of Chemistry and Physics 86TH Edition 2005-2006", it says : 0.134 g/100 g water at 25 deg C; soluble in acid. Based on Wikipedia, it is much less soluble in water and soluble in HF. Some chemical websites show that it's soluble in H2SO4, HNO3, however, insoluble in HCl. I was confused. From my practice, it works, but i wanna know the correct chemical equation. More valid information, details will be better, thanks a lot!
I am going to perform a membrane autopsy of a reverse osmosis membrane to investigate fouling. I know how to do it based on research papers that i have read but I need a standard procedure describing the steps to be followed.
I recently computed an Absorption and Emission Spectra of AlexaFluor fluorescent Dyes (AF-488 & 594) using TD-DFT/B3LYP/6-31+g(d,p)/DMSO/IEFPCM-Solvent Model. I also tried with CAM-B3LYP but the results are same.
What I've got is that my computed spectra are much broader over a long range of wavelength in comparison to the experimental spectra. Can someone please give a explanation for this? Although I've reached a comparable lambda max, yet my spectra are much broader.
I've attached the Experimental and Theoretical Spectra of AF-488, Yellow line: Theoretical || Blue-Line: Experimental
Thank You :-)

I'm wondering if you could suggest highly viscous solvent which is non-polar or slightly polar and can't form H-bond interactions.
Most preferrably: a glass forming solvent at low temperatures to be used in UV-Vis measuremens.
Generally, most of the research papers talk about the performances of a Li-ion half cell, coin cell or pouch cell. Do those performances are comparable with other shapes (cylindrical, prismatic) of lithium ion cell of same chemistry?
Hello,
I need to prepare a polyethylene glycol hydrogel, but have only limited supply to chemicals, so is there any crosslinking agent (except citric acid) that I may have access to and is able to crosslink PEG, preferably at room temperature.
Physical crosslinking like freezing and thawing (does probably not work) is also a possibility and would be preferred by me, because else I have to exchange the crosslinker-hydrogel polymer with my battery electrolyte, which takes a lot of time.
"At the moment only about 300 ionic liquids are commercialized" This information I have get from one Chemistry thesis of 2017. In the case of Ionic liquid based surfactant what should be number? How to get this information?
Thanks in well advance
I have tried Felder, Smith & Vaness, Perry, Dean, among other chemistry books and I still can´t find the heat capacity constants for Diethylene glicol and ethylene glicol, does anyone know another source? Thanks!
Hello,
for already determined distribution coefficients in different systems aqueous solution/resin, via gamma spectroscopy, Is there a way to determine a stability constant in order to strengthen the description and discussion of the data?
The only available data is the gamma measurements.
Redoing the experiment via the pH determination will be an entirely different endeavor.
Is it possible to create some nanostructure so as to absorb the entire solar spectrum. If not then What are the major challenges in this field...?
I have a multilayer film (A/B/C/PET/PE). PET and PE are the last layers. I want to laminate this multilayer film to another PE film in a PE to PE manner (A/B/C/PET/PE-to-PE). The lamination is not working properly. What could be the cause? Can PET affect the chemistry of PE
Hi all
I have an equation of the form
CxHyOz---->(decomposition) aCO + bCO2 + cCH4 +d H2
how can i get the values of a, b, c and d from elemental and proximate analysis of biomass?
x,y,z are unknowns
Thanks

I want to do a chemistry between two compounds. Only the amine groups of both these compounds are free for conjugation with each other. What linker is best suggested for the process?
I researched two highly cited journals publications (2017-2018) and observed that more than 55% papers on very specific research topics are published by 13 research groups from 5 countries. Is really only 13 research groups are capable for the highly cited research load of the world?
what exactly the NaCl does to the surfactant means what is the chemistry involved ? Does it have any relation with the CMC ?
Hi all,
I have some confusions regarding ultimate (elemental) and proximate analysis
1) Should the sum of all percentages be always 100 (for both analyses)?
(Figure 1 attached, doesn't make sense to me)
for balsa wood, C+H+N+S=100
for Eucalyptus, Ash+C+H+N+S+O=100
for rice husk, Ash+C+H+O=100
2) Is ash included in elemental analysis?
3) Is elemental analysis always based on dry/wet basis. what should we consider (dry or wet) if not mentioned?
4) If in elemental analysis, sum of all elements percentages equals 100, and humidity is also given (additional to 100%), then what is it, dry or wet basis elemental analysis? (figure 2)
Thanks


Evaluating academic faculty for promotions often include assessing their teaching abilities. Is it sensible to base these on Student Course Evaluations?
Geoffrey Alderman wrote in the Gaurdian that a reason for the decline in academic standards has been the 'increasing and increasingly stupid use of students' course evaluations as pivotal factors in the academic promotion process.'
Does anyone have a deeper insight on how the use of such student evaluations have impacted faculty at their own institutes? Have they led to dumbing down?
How much confidence would you have in the teaching ability of the applicant if the evidence was exclusively based on Student Course Evaluations?
I'm not an expert in chemistry but I hope it to be a straight forward question.
The situation is, as shown in the figure below, I'm trying to etch a semiconductor in KOH solution (4M concentration) at room temperature. There is a negative sheet charge with a density of P (C/cm2) located at the bottom surface which repels the OH- from accessing the semiconductor. However, the etching can progress along the sidewall until the distance (d) is too close and the diffusion force and electric field reach an equilibrium. I'd like to know how to calculate this distance d. Thanks in advance.

I am interested in new Sn(IV) based products, without a direct bond to a C-atom , what makes these products not toxic.
Is your work going into this direction , or is it more for anti-fouling applications?
Thanks for your information.
Best regards,
Dr.Joop Koster
JBK Research & Consulting
CH-1260 Nyon
Switzerland .
I am looking for a procedure of determining nitrates and phosphates in water samples using UV-Vis.
By best, I mean which could easily extract out soil organic matter such as amino acids plus which could easily be available or synthesised using basic chemicals.
I was wondering if anybody has worked with chemistry of these two cross-linkers and have characterised by FTIR or MS whether they are cis/trans or S/R isomers?
Apologies: I am not a synthetic chemist by training.

Hi,
I am trying to modify sulfonic acid group to conjugate with carboxylic group or amine group in protein.
I have hard time finding chemistry to modify sulfonic acid for the conjugation.
Can anybody let me know if there are options?
Thanks
best,
I am wondering if one could ideally create a formula inputting the stokes/hydration radius of the ions involved and the charge of the ions to estimate the change in melting/boiling point of water per gram of salt used?
I am not sure if a direct correlation can be made using the hydration radius, but my intuition tells me that an ion which strengthens the hydrogen bonds between the water molecules (like e.g. Lithium which has a large stokes radius) should be able to increase the boiling point of water by a few degrees, whereas an ion which destabilises the hydrogen bond cluster (and therefore has a small stokes radius) like Rubidium should decrease the melting point of water.
There are many predatory journals online available and also growing day by day. How to detect that the journal is predatory, As I found there is site where there is list of predatory journals but how we will come to know these sites information is correct or not?
Any other way to find out?
As there is continuous threat that somebody may waste their data in publishing in these journals.
I am preparing an optical system in infrared, however I will need to stick two optical components. They are made from CaF2.
Can you recommend index matching-liquid? I am interested in the range 1um-15um. I see that other researchers use paraffin oil, but still i would like to make sure of all possibilities.
Or maybe there are few liquids, that would work eg. in 1um-5um, 5um-10um and so on?
I have two questions.
1) I have a molecule H2N-R-NH2, and I want to react one end using amine coupling reaction to attach SH as the terminal group. That is to day, the final structure is H2N-R-(linker, preferably alkyl chains)-SH. Does anyone know what is the selectivity (one-end functionalization or two-end functionalization) for amine coupling reaction? And is it to purify?
2) I have NC-R-CN, and I want to attach one end to get SH as the terminal group, i.e. NC-R-(linker)-SH. What chemistry is feasible?
Any recommendation on the literature is more than welcome.
I want to know how I can find a specific structure of metal organic frameworks?
I need a molecular structure of Ag-BTC MOF.
How can I get it?
Can anyone help me on this?
Hello Respected Seniors!
I want to collect samples from the Acid Mine drainage environment to determines the microbial community in that sample. So how we can collect the sample that the chemistry and biology of the sample are not disturb and we can get a significant result.
Hope that i will get a positive response.
Thank you so much.
Hi everyone,
I'd like to verify if my solid phase extraction cartridge is saturated after i tried to purify a serum sample potentially containing drugs?
Thank you
hi Experts
I want to estimate and differentiate the different forms of potassium such as potassium chloride, potassium sulfate and potassium carbonate in the plant ash samples. Please suggest me the best methods and how could i achieve my goal.
Dear Friends,
I am working on a R&D project about increasing alkaloid content of Papaver sp. in in vitro conditions. My project manager asks me to isolate codeine from total alkaloids extracts from Papaver culture. Since I have no opinion about the procedure I checked online procedures and only find out cold water extraction way which is not suitable. I have to isolate the final product as pure as possible. Do you have any suggestions about it?
Thanks for your kindly and helpful replies.
Hello,
I am trying to make a pH controller with Arduino using a solenoid valve. I want to be able to open my valve for a certain amount of time and lower the pH by X amount in a bucket. I am using phosphoric acid. My first question:
Let's say the pH is 8 and I want to reduce it to 7:
0) If the pH is 8 in the bucket this means a concentration of 10-8M?
1) How do I know which acid dissociation constant pKa to use 2.16 or 7.2 or 12.32 (7.2 because it's closest to my target pH?)
2) Next how to I use the HH equation pH = pKa + log ([H2PO4-]/[H3PO4]) ?
3) Lastly how to I account for volume in the bucket I'm trying to change the pH of ?
EXTRA:
4) Any idea how to account for flow rate out of the valve?
Thank you so much!!
I want to know if there is a time or duration that is expected for AOC to change and cause bio-film development on membranes. This question is also applicable to pipelines for water distribution. Although the conditions for these two scenarios may differ due to several factors like material properties (membrane and pipes) and surrounding chemistry
Does anybody know about a free electronic laboratory notebook suitable for synthetic organic chemistry experiments? It should be preferable in a software version, not online. Thanks for your help.
When you create pectin from orange peels, lemon juice is added to neutralize the pH and also to neutralize the negative charges in the pectin. How come strands of Pectin contains negative charges? Will adding lemon juice to the orange peels neutralize the negative charges? Also, they use lemon juice in jams, when creating pectin.
After synthesizing polymer-drug conjugate via a carbodiimide chemistry, is there any other way to confirm the conjugation between the polymer and the drug apart from NMR, FTIR and UV-vis? Can LC-QTOF plays a part in the conjugation confirmation?
Thank you very much.
Dear All,
I have a pH electrode of BNC probe type ,which will give the output as mV .Can any one help me to convert sensor mV values into respective pH values .
Any suggestions /help is highly appreciated .
Hello,
I am trying to use microwave irradiation to synthesis a schiff base using salicyladehyde and phenylamine. Do i need to use a metal like CuCl2 to coordinate the reaction?
I developed a device for cutting the TLC plates. This is my new invention and this design is registered. I wish to commercialize this product.
Please let me know if it is useful for daily chemistry purpose.
How does this reaction happen that makes the mustard move around in certain path, is there a pattern for this?
I want to ask if determining the seed oil content using gravimetric means such as done in the paper below is appropriate.
There were no chemicals used.
I could not find any other literature supporting this method.
If there are, can you share this with me? please.
Thank you very much.
Some special drugs might be deformed and deactived next to high temperature so it cause many damages for their Productive factory
What are important topics for research in the field of organic chemistry?
Its just clearly mentioned on the article below:
"The chemistry of minerals obtained from the combustion
of Jordanian oil shale" written by: A.Y. Al-Otoom et al.
For example, total number of molecules of Mn, S and O in MnSO4. I only know the molar mass and the total mass I have to prepare. I do not know the number of moles or molarity.
I have my ZnO nanoparticles and I have to check the zeta potential at various different pH range from 2-12. But usual chemistry of ZnONP tells that they might start dissolving below 5.5 pH or so. In such case how do I go about?
How to prepare sample for just normal zeta measurement and for various pH? Which solvent (I use deionized water as of now)? Concentration?
If i choose phosphate buffer at various pH does that help?
I am very new to this method I have never done this before so I have no clues. If someone can guide me through how to go about from sample preparation to interpretation.
Can DLS be measured with same sample preparation?
Ifosfamide is one of the most famous and useful drugs for cancer but its very important that you know this pharmaceutical compound has many harmful effects on sick people , one of which is bleeding that is very danger for them and it might be so unbearable .
What is spiral modulated spin structure in ABO3 Perovskite (ferromagnetic material) ?
I recently conducted a coffee-cup calorimetry experiment in which we attempted to measure if the dissolution of inorganic crystals such as LiCl, NaCl, and SrCl were endothermic or exothermic based on a change in temperature over time plot, including measure the enthapy of solutions, but I'm not sure how to do that.
Methods:
We measured 7.9204 grams of SrCl2, 4.2143 grams of LiCl, and 2.9290 grams of NaCl and decanted these into separate coffee cups filled with 50 mL of deionized of water. (These were about 1 - 2 mole/liter solutions.). A temperature probe measured the temperature change over 600 seconds, recording a measurement twice a second. I've only displayed about 140 seconds of the measurement, because the temperature was just continually oscillating 0.1 degree Celsius after that point as it reached equilibrium.
We made plots for each of the chemicals, where an increasing curve shows an exothermic reaction, and an endothermic reaction displays a decreasing curve. Over time, these solutions (Temperature ~ Time) curves should equalize to equilibrium.
Theoretically, we predicted we could determine if the enthalpy of solution like so ...
Enthalpy of solution = Lattice Enthalpy + (Hydration Enthalpy of cation + Hydration Enthalpy of Anion),
where the Lattice Enthalpy is a measure of the stability of the compound crystal which is at least a function of the charges of the cation and anion, as well as their size, and the structure of the crystal body centered cubic vs face centered cubic, and the hydration enthalpy is the energy it takes to dissolve the gaseous ions after breaking the crystal lattice.
Schematically, the Lattice Enthalpies ( Δ H):
LiCl(s) ----> Li+ (g) + Cl- (g); ΔH = 852 kJ / mole
NaCl(s) ----> Na+ (g) + Cl- (g); Δ H = 787 kJ / mole
SrCl2(s) ---> Sr2+ (g) + 2 Cl- (g); ΔH = 2153
Source:
These Lattice Enthalpies were obtained from Table 18B.4 of my textbook:
Physical Chemistry Thermodynamics, Structure and Change, 10th Edition, VOlume 1, by Peter Atkins & Julio de Paula
Then the Enthalpies of Hydration are these:
Li^(+) (g) ---> Li^(+) (aq); ΔH = -519 kJ / mole
Cl^(-1) (g) ----> Cl^(-1) (aq) ; ΔH = -381 kJ / mole
Na^(+) (g) -------> Na^(+) (aq); ΔH = -409 kJ / mole
Sr^(2+) (g) -------> Sr^(2+) (aq); ΔH = -1443 kJ / mole
Source of Enthalpies of Hydration (Tables 1 - 2):
The Enthalpies of Hydration that I've used are experimental.
Smith, Derek W. "Ionic hydration enthalpies." Journal of Chemical Education 54.9 (1977): 540.
Therefore, the enthalpy of solution for LiCl, NaCl, SrCl2 is this:
For LiCl,
ΔHsolution, LiCl = (852 kJ / mole) + [(-519 kJ / mole) + (-381 kJ / mole)] = -48 kJ / mole < 0, so this reaction should be exothermic and it is as predicted.
For NaCl,
ΔHsolution, NaCl = (787 kJ / mole) + [(-409 kJ / mole) + (-381 kJ / mole)] = -3 kJ / mole < 0, so this reaction should be exothermic.
I've been searching the web about this reaction and most sources say it's endothermic which I my graph shows, but my calculations do not show that. What?
Doing the same kind of mathematics, the Enthalpy of solution for SrCl2 is this:
ΔHsolution, SrCl2 = [2153 + (-1443 - 2 * 381)](kJ / mole)
= -52 kJ / mole < 0, so this reaction should be exothermic.
BUT MY PLOT SHOWS that It's significantly endothermic!
What's going on? Is my mathematics faulty. Am I using too concentrated solutions? Is the SrCl2 that we are using impure or not really SrCl2? I suppose that's possible, but we didn't do any validation because this lab took quite some time. How is it possible that my experiments don't match theory mostly?
Thank you for you for your help.

I'm going to make a suspension of Carbon black in order to mix it with another water base suspension and freeze-dry it. considering the point that carbon black does not mix with water properly I need to use another solvent. I tried DMAc but my sample melted during freeze-drying!!! I'm wondering what would be the best option?
Thanks
By looking at the structure of both molecules, I see that both molecules have at least two non-conjugated sigma bonds, making conductivity due to resonance seemingly impossible. I read from this paper " " that the conductivity of polystyrene is about 6.7*10^-14 S/m and polypropylene should have a conductivity somewhere between 10^-18 and 10^-17 S/m.
Some things I didn't consider is the density and porosity of the materials and possibly inter-molecular effects.
jcr based impact factor not the other one.
What are the basic mechanisms or processes that occur polarization in dielectrics?
what are the basic differences between 1) Electronic polarization 2) Ionic or atomic polarization 3) dipolar polarization 4) Interfacial polarization?
how to determine indirect band gap using UV-VIS-NIR Spectroscopy ?
how to draw Cole Cole plot Z vs Z' using impedence Analyzer with explanation ?
How to increase the surface activity of low surface energy plastics?
How to make the surface of polyolefins Chemically active ?
Suggest me some practical ways to achieve it.
Which techniques are currently being used to bond low surface energy plastics ?
How much bond strength can be obtained at most on plastics like LDPE, HDPE, PP?
Any rubber based Adhesive being used for such application?
I'm looking for the chemical reaction(s) involved in EROD assay to get a deeper look at its working principle. I've read abut the basic principle mentioned in number of papers, but i haven't come across one which tells about the chemistry of the assay in detail.
Also, which is the best database to find chemical reactions?
Today, every educational field or domain contains several branches. You first choose one branch of your field to prepare your Master and Ph.D degrees. What is preferable system for you:
1- study the same branch at both Master and Ph.D degrees
or
2-study different branch at Ph.D degrees from Master degree
And, Why?
why is the color of PbSO4 in lead acid plates is black instead of normal white color for lead sulfate after the plates is discharged in lead acid battery ?
First run of generating the polythionics APPEARED to work, got a turbid white solution with smell of sulfur but 304SS coupon did not crack. I'm looking for particular details about the reagent or setup that will lead to successful test on sensitized coupon of 304.
What can be the best alternative for EDC, DMAP as catalyst for carboxylates? I want to skip DMAP actually.
Hi Dear All,
Boronic acids in general form complexes with cis 1,2 or cis 1,3 diols etc. If we want to protect the boronic while attaching it to any polyesters with multi hydroxyl groups. Could somebody give a nice idea to do that?
Kind Regards
Hi All,
Could some one suggest an easy and efficient way to protect phenyl boronic acid with ethylene glycol?
Kind Regards
I read in an article where I found the term plasma activated HCL , I was wondering how to achieve that?
How to select the active moiety in any aqueous extract and the chemistry of it?
Dear all,
I need good and up to date resources to find out the applications of nanotechnology at industry.
Thanks
Metal oxides can be functionalized easily with any matter but why it is not possible to functionalize metal sulfides with materials such as for example their fictionalization with an Aerogel?
I want to conjugate streptavidin with some different peptides to make a target for biotinylated antibody. Need a protocol to do this.
I'm interested in identifying examples of high-U and/or Th overgrowths of zircon of magmatic origin. Apart from metamictisation, what features/textures/chemistry are associated with this style of overgrowth?
