Unanswered Questions
209 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. ...
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Why is there preferential adsorption of a common ion during preparation of colloids by peptization?
There was a similar question asked here on Chem SE, but the answer was not very satisfactory to me, so I am asking a fresh question.
Peptization is the process of creating a colloid from a precipitate ...
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Is there an adhesive that is not dissolved by acetone?
I am trying to glue glass sheets together to make a sealed 13" x 13" x 13" box. Inside this box there would be acetone gas used to melt 3D printed parts to make them more durable. Acetone will remove ...
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4
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Solubility or reactivity of tantalum carbide and potassium polyselenides?
It is probably an unexplored system, but is there anything known about the low temperature thermodynamic equilibrium state of this?
By 'tantalum carbide', I mean $\ce{TaC}$, and by potassium ...
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4
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1
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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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4
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Why is there a large increase in volume when an alkali metal is dissolved in liquid ammonia?
My teacher said unexplainedly that when alkali metals dissolves in liquid ammonia, there is a large increase in the volume. I found a paper that confirms this fact [1]:
In the course of recent ...
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4
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691
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Theory of volume contraction in solution
When a solid is dissolved into a liquid, or two solids are amalgamated, their mutual volume will contract. For example, a crystal of sugar having a volume of one cubic inch dissolved into 10 cubic ...
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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 ...
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Synthesizing monodisperse PbS quantum dots
For a research project, I am trying to synthesize lead (II) sulfide quantum dots using the method of Li et al.. I am injecting sulfur dissolved in 1-octadecene into a mixture of $\ce{PbO}$, oleic ...
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4
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How do xanthan gum and other hydrocolloids work?
Does anyone know what causes things like xanthan gum to make water into a slimy substance on the molecular level?
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4
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1
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In the nonideal solution, why can't one of the solute be positive deviation and the other be negative deviation?
In the nonideal solution, why can't one of the solute be positive deviation and the other be negative deviation?
Let's say A and B makes a nonideal solution.
The moleculat force between A and B means ...
CommunityBot
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3
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Is double excitation of nitrogen possible, and would it be able to use it as a central atom in a coordination complex?
I’m 17 and in my 2nd year of high-school (we have it a tad different here in the Czech Republic) and am interested in theoretical chemistry so that’s the explanation of the nature of my question.
So, ...
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3
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What is the goopy substance that forms before CaCO3 precipitates?
I do a lab where we mix a solution of sodium carbonate with a solution of calcium nitrate. As expected, calcium carbonate (white solid) precipitates out. However, if the concentration is high enough, ...
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How to calculate composition of alcohol/water mixture to achieve given concentration of alcohol vapors in air for calibrating a DIY breathalyzer?
I made a breathalyzer using a MiCS-5524 gas sensor. I would like to calibrate it so it can be close to accurate. e2v technologies — MiCS Application Note 4, Using MiCS Sensors for Alcohol Detection (...
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3
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How does the surface to volume ratio of ions and their distribution in solution compare to that of suspended nanoparticles in nanofluids?
I am interested in understanding the heat transfer capabilities of fluids.
Nano-fluids are suspensions of nanoparticles (1-100nm sized particles) in a base fluid, often water, oil or glycol. These ...
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