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Unanswered Questions

524 questions with no upvoted or accepted answers
7 votes
0 answers
135 views

Metal hydrolysis and equilbrium constants from stability constants

Problem: I want to create minimum solubility plots for a series of metal hydrolysis species against pH (below). But I cannot reconcile literature stability constants and equilibrium constants. Context:...
6 votes
0 answers
171 views

Which xylenes, if any, are immiscible with DMSO?

"Xylene" is reported to be immiscible with dimethyl sulfoxide (DMSO), according to a few solvent miscibility tables found online (chart 1, chart 2, chart 3). I have tried to locate some ...
6 votes
0 answers
164 views

Why is supersaturated sodium acetate so (meta)stable?

Sodium acetate is a common example used in general chemistry lectures to illustrate the idea of supersaturation, and that precipitation of a supersaturated solution can be initiated by a seed crystal. ...
6 votes
0 answers
67 views

Using Le Chatelier's Principle to Change Mechanical Energy to Chemical Energy

I was interested in an application of Le Chatelier's principle, where an increase in pressure could result in a decrease in the moles of gas. In particular, a situation where when the pressure ...
6 votes
0 answers
775 views

How can copper(II) sulfate crystallize outside a glass vial?

I'm making copper sulfate crystals in glasses. Within a few weeks, the copper sulfate seems to crystallize both inside and outside the glass: (A few weeks after making a new solution) (Yet another ...
5 votes
0 answers
187 views

What pH value of 1M sodium crotonate solution supposed to be?

I need to prepare the $\pu{1M}$ solution of sodium crotonate, however, I don't have one in lab, but I do have sodium hydroxide and crotonic acid. Thus, I calculated that for $\pu{100 mL}$ of $\pu{1M}$ ...
5 votes
0 answers
793 views

Solubility of PbSO4

The solubility of $\ce{PbSO4(s)}$ increase with the addition of $\ce{H2SO4}.$ Why? I don't quite understand this. When dissolving $\ce{PbSO4(s)}$ we get the equilibrium equation: $$\ce{PbSO4(s) <=...
5 votes
0 answers
479 views

Why does pKw first decrease but eventually increase when temperature rises?

I understand the initial decrease in pKw. $\ce{Heat + H2O (l) <=> H+ (aq) + OH- (aq)}$ Temperature increases, reaction shifts to the right, so $\ce{H+} \text{ and } \ce{OH}$ ...
5 votes
0 answers
98 views

Equations Used in Isothermal Titration Calorimetry

I have been attempting to understand and derive the formulas used for ITC which can be found here starting on page 310. I am particularly interested in the single set of identical sites. To first ...
5 votes
0 answers
159 views

Where is my antimony going?

I work in a trace metals laboratory operating an ICP-OES. I've been having some trouble with the recovery of antimony in a weak $\ce{HCl}$ solution post-digestion. The antimony is part of a mix of ...
5 votes
0 answers
5k views

Should I round an experimentally determined reaction order to an integer?

For a lab experiment I did, I calculated the reaction order for one of the reactants using data from two trials, both rates, and the concentration of that reactant during each. $$ \frac{\text{Rate}_1}{...
5 votes
1 answer
553 views

What does the equilibrium constant mean for reactions with very small concentrations?

When you calculate the equilibrium constant for a reaction with a higher concentration of reactants, the answer is fairly intuitive. For example, for the reaction: $$\ce{A + B <=> C}$$ when we ...
4 votes
1 answer
234 views

How does a silver chloride electrode (Ag/AgCl) convert the potential in aqueous solution to the wire?

I am aware of the redox chemistry that happens at the electrode surface, but I'm not sure how exactly a change in electrical potential in the solution would change the potential in the electrode?
4 votes
0 answers
86 views

Notation for spectral density in experimental community

In an open quantum system setup where the system is coupled to infinite harmonic oscillators as bath (as in the Caldeira leggett model, for example), through the Hamiltonian, $$H = \frac{\hat{p}^2}{2m}...
4 votes
1 answer
366 views

Variation of conductance of saturated aqueous solution with temperature

The following question was asked in JEE Mains 2020: Let $C_{\ce{NaCl}}$ and $C_{\ce{BaSO4}}$ be the conductances (in S) measured for saturated aqueous solutions of $\ce{NaCl}$ and $\ce{BaSO4}$, ...

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