Unanswered Questions
315 questions with no upvoted or accepted answers
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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. ...
- 71.6k
6
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775
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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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322
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Conductivity measurements of demineralized water - Unexpected results. Looking for explanation
I'm trying to measure the conductivity change of demineralized water over a few days. But I get results I can't explain.
Setup
This is the circuit and cell I'm using:
Where $R_x$ is the ...
5
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0
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187
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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 $\pu{1M}$ ...
- 151
5
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793
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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:
$$\ce{PbSO4(s) <=...
- 38.4k
5
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113
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What is the arrangement of water molecules in a hydration shell around an anion?
I believe I read somewhere that the hydration shell of ions always has hydrogen on the outside, but I can't relocate the exact whereabouts of this. Thus, I decided to ask here, as to what the ...
- 187
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159
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Where is my antimony going?
I work in a trace metals laboratory operating an ICP-OES. I've been having some trouble with the recovery of antimony in a weak $\ce{HCl}$ solution post-digestion.
The antimony is part of a mix of ...
- 17.6k
4
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1
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234
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How does a silver chloride electrode (Ag/AgCl) convert the potential in aqueous solution to the wire?
I am aware of the redox chemistry that happens at the electrode surface, but I'm not sure how exactly a change in electrical potential in the solution would change the potential in the electrode?
CommunityBot
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Notation for spectral density in experimental community
In an open quantum system setup where the system is coupled to infinite harmonic oscillators as bath (as in the Caldeira leggett model, for example), through the Hamiltonian,
$$H = \frac{\hat{p}^2}{2m}...
- 91
4
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1
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366
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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 $\ce{BaSO4}$, ...
CommunityBot
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107
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Can this happen to superheated water?
Superheated water refers to water that is heating well beyond its usual boiling point under extreme pressure. This cause it to display anomalous property.
I noticed that as temperature increases, so ...
- 38.4k
4
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254
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Why does viscosity decrease when divalent cations are dissolved into aqueous solutions of sodium carboxymethylcellulose?
Sodium Carboxymethylcellulose (CMC/NaCMC/Aqualon) is a common product used in many instances for its unique properties, especially its ability to make solutions viscous. It is well known that the ...
- 1
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592
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Brewing tea with deionized water
I am wondering what efect brewing tea (let us assume for the sake of simplicity it is green tea, brewed at about 80 °C) in deionized water might have on the product.
Will the lack of ions in the ...
- 457
4
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312
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Debye-Huckel theory with non-polar solvents
I want to calculate the activity coefficients of mixed solvent salt solutions. I am seeing very strange behavior when I try calculating the activity coefficient of salts in non-polar solvents using ...
- 1,690
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How to break down soap and detergents?
I am building a greywater harvesting system. It is a 3-stage system:
The 1st stage breaks down soap and detergents.
The 2nd stage filters the water.
The 3rd stage pumps water out of system.
What ...
