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Unanswered Questions

241 questions with no upvoted or accepted answers
3 votes
0 answers
191 views

Can there be an aqueous solution with a convex meniscus?

This question is motivated by a quote from a TV show: A detective is looking at a small vial (really a glass tube) that supposedly contains poison. Then the detective says: You don't have to take AP ...
3 votes
0 answers
1k views

Number of moles of acidified potassium dichromate required to liberate 6 moles of iodine from an aqueous solution of iodate ions

I came across this question in a recent exam I had taken: How many moles of acidified $\ce{K2Cr2O7}$ is required to liberate 6 moles of $\ce{I2}$ from an aqueous solution of $\ce{I-}$ ? So this is ...
3 votes
0 answers
497 views

The most convenient process to purify Oxalic Acid up to a high level of purity

I am set out to purify a batch of commercial oxalic acid with the aim in mind to end up with a highly pure product (starting from $\pu{4,000 ppm}$ total impurities and doing so with basic lab ...
3 votes
0 answers
116 views

Molar ratios not leading to complete reaction in Schweizer's reagent production

In my home lab, I've reacted $\ce{Cu(OH)2}$ with aqueous ammonia to produce Schweizer's reagent. However, I'm surprised by the amount of ammonia required to react with this amount of $\ce{Cu(OH)2}$. ...
3 votes
0 answers
157 views

Removing Tungsten Trioxide from Tungsten Electrode

I need a very sharp tungsten electrode, and I think radial electrochemical etching with sodium hydroxide is the way to go. The problem therein (I think) is that the etching will cause an oxide layer ...
3 votes
0 answers
1k views

Calculating total volume mixing NaCl and water

I'm (as a non chemist) trying to calculate the the volume of a NaCl solution. The problem is that I know the volume of water prior to mixing in NaCl, but I want to know the volume of the solution ...
3 votes
0 answers
160 views

Chemistry Behind TMOS Aerogel

I have found out how to make silica aerogel. Currently, the solution that I need to create to make the gel requires tetramethyl orthosilicate or TMOS. Furthermore, the procedure requires me to make ...
3 votes
0 answers
342 views

Hydrogen Peroxide Heat of Dilution

Based on some data here, I am getting the heat of dilution of 100% $\ce{H2O2}$ as approx. 1100 cal/mole. That's about 4.6 kJ/mol if I did my math right. Is this a correct value? Seems too low to ...
3 votes
0 answers
110 views

Poor aqueous solubility of chloroazodin

Below is the structure of chloroazodin: Why is chloroazodin poorly soluble in water? It has multiple amine and imine nitrogens, all of which appear to be available for hydrogen bonding, and thus it ...
3 votes
0 answers
80 views

Can a brine water electrolysis be looped?

Electrolysis of brine yields hydrogen and chlorine gases and aqueous $\ce{NaOH}$. So is it possible to combine the gases to form $\ce{HCl}$ gas, and mix it back with the aqueous $\ce{NaOH}$, so it ...
3 votes
0 answers
290 views

If both nitric acid and nitrate ion are stabilised through resonance, what makes the nitrate ion more stable in aqueous medium?

If both nitric acid and nitrate ion are stabilised through resonance, what makes the nitrate ion more stable in aqueous medium? Can the same argument be applied to nitrous acid and nitrite ion in ...
3 votes
0 answers
633 views

The Health Effects of Alkaline Ionized Water?

I came across alkaline ionized water as my aunts bought a system called Kangen Water from Enagic Inc. The water produced by this system is claimed to contain smaller water clusters (4-6 molecules) ...
2 votes
0 answers
38 views

Salts solubility and speciation calculations using PHREEQC

I am collecting data from literature for CO2 solubility in aqueous solutions. These are usually synthetic brines and are reported as molalities or wt% of salts or salt mixtures (I have NaCl, KCl, ...
2 votes
0 answers
69 views

Stability of n-Dodecyl-beta-D-maltoside in buffer solutions for assay experiments

I have a buffer system which contains multiple salts and in addition DTT and n-Dodecyl-beta-D-maltoside. I understand that DTT is hydrolysing quite fast and this component must be used always fresh ...
2 votes
0 answers
88 views

Why do buffer solution only maintain pH to a certain limit?

I know that buffers have a capacity after which they are not able to maintain a relatively stable pH. This capacity is exceeded when we add too much acid or base but I was wondering why does this ...

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