Unanswered Questions
606 questions with no upvoted or accepted answers
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Which potentials are suitable for molecular dynamics simulation of simple explicit solvents?
Which potentials (force fields) are suitable for adequately simulating (mixtures of) explicit solvents? Interesting rheological properties include viscosity, surface tension, heat capacity.
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Cobalt Chloride in various solvent/water mixtures - tested
In a recent post the solvatochromic behaviour of cobalt chloride in acetone was discussed. There were some ideas how the acetone might influence the ratio between the blue $\ce{[CoCl4]^2-}$ and the ...
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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:...
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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 ...
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Are all humectants sticky?
While using a topical lotion based on ethanol, water and propylene glycol, I noticed that it becomes sticky while drying. Propylene glycol is a humectant and is used for this purpose in ...
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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. ...
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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 ...
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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 ...
- 17.5k
6
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Dissolving ability of octane vs nonane on neoprene
I have been working with straight chain octane and nonane. The neoprene seals in some parts of the apparatus are allegedly far more vulnerable to the deleterious effects of octane than nonane - why? [...
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How to dissolve a strong resin in difficult situation?
The resin is made up from two components:
Component A: silicic acid, sodium salt (less than 10% sodium silicate)
Component B: Diphenylmethane-4,4'-Diisocyanate, isomers and homologs (MDI,Polymer-MDI)...
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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 $\pu{1M}$ ...
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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) <=...
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479
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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
$\ce{H+} \text{ and } \ce{OH}$ ...
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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 ...
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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 ...
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