Questions tagged [solutions]
This tag should be applied to questions dealing with solutions of any kind. A solution is a liquid or solid phase containing more than one substance where, for convenience, one (or more) substance(s) called the solvent is treated differently from the other substances, which are called solutes. If water is the solvent, then the more appropriate 'aqueous-solution' tag should (also) be specified.
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Is calcium chloride an acidic or basic salt?
What I reason:
Calcium chloride is the salt of hydrochloric acid and calcium hydroxide. Calcium hydroxide is usually not considered a strong base, and I believe this is because of it's low solubility. ...
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Gibbs Free Energy of Solutes and Solutions
Using the equation $$\ce{CaSO4 (s) <=> Ca^2+ (aq) + SO4^2- (aq)},$$ and $\Delta H/\Delta S$ values, calculate $\Delta G$ at $50~^\circ\mathrm{C}$ when the solution is saturated with $\ce{Ca^2+}$ ...
7
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497 views
Dissolution of Lithium in Methanol
Easy question to kick off my chemexchange membership!
I'm learning chemistry in my spare time, and fittingly for a video art project I'm doing, decided to try a simple inorganic(?) procedure to make ...
7
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1answer
362 views
Periodically oscillating chemical reactions?
I've seen before chemistry demonstrations where solutions are mixed with one another and subsequently where the resulting product goes through periodic color changes: for example blue to orange and ...
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1answer
6k views
Difference between ideal & ideal-dilute solution
These two terms has been frequently used in Physical Chemistry by Atkins. He describes Raoult's Law using ideal solution while Henry's law using ideal-dilute solution.
I thought, at first they were ...
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5k views
Proportion of gases filled in cylinder of sea-divers
In my book it is given that earlier cylinder were filled with 2% oxygen and 98% helium. Nowadays it is filled with 11.7% helium, 56.2% nitrogen and 32.1% oxygen.
There are few questions which come up ...
7
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2answers
195 views
How do phase transfer catalysts bring anions to organic phase?
Many anions are quite stable in the aqueous phase, but not so much in organic solvents where its necessary to perform some reaction (usually nucleophilic substitutions). I have heard that crown ethers ...
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3answers
1k views
How much calcium hydroxide will precipitate after addition of sodium hydroxide into saturated calcium hydroxide solution?
Below was question 34 in the USNCO 2017 exam:
If $\pu{0.10 mol}$ of solid $\ce{NaOH}$ is added to $\pu{1.00 L}$ of a saturated solution of $\ce{Ca(OH)2}$ $(K_\mathrm{sp} = \pu{8.0 \times 10^-6})$, ...
7
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579 views
Can I equalise osmotic pressure using two different solutes?
I understand that there is a pressure gradient between an aqueous solution, e.g. salty water, and, say, pure water due to osmosis. My question is, is it possible to match or almost match, the osmotic ...
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1answer
233 views
Is it possible to have Volume(solution) < Volume(solvent before adding solute)?
I understand the answer to the question "Is it possible to have Volume(solution) < Volume(solvent) + Volume(solute)?" is "yes" -- but it is possible that adding a solute causes the solvent to ...
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3k views
Alkaline glycine buffer molarity
Having never prepared a buffer solution before, I am hoping for a little help in understanding the process.
This method I plan to use calls for a $\pu{0.1M}$ glycine buffer at pH $10.6$. Some ...
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Dissolve Silver Oxide
I was looking at how to dissolve silver oxide (in a solvent). I know that monovalent silver oxide will not dissolve in water, but are there any solutions in which monovalent silver oxide will dissolve?...
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37k views
Difference between solubility and dissolution?
How is solubility different from dissolution? And how are they both different from solvation?
6
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1answer
5k views
Titration of sulfuric acid with sodium hydroxide
$55.0~\mathrm{mL}$ of $0.250~\mathrm{M}~\ce{NaOH}$ is used to titrate $35.0~\mathrm{ml}$ of $\ce{H2SO4}$.
What is the molarity of $\ce{H2SO4}$?
I know that the equation for this reaction is:
$$\ce{...
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1answer
29k views
Degree of association, van't Hoff factor and dissociation constant
$\ce{CH3COOH->CH3COO- + H+}$
\begin{array}{c|c c c}
\mathbf{Initial} & \mathrm{1~mol} & \mathrm{0~mol} & \mathrm{0 ~mol} \\\hline
\mathbf{Final} & \mathrm{1-\alpha ~mol}&...
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2answers
5k views
Spontaneous explosion of a bottle containing alcohol and milk
A friend of mine gave me a bottle of home-made liquor which is a concoction of pure alcohol and sweetened milk. I accepted his gift happily and then I put the bottle in my cocktail cabinet. After an ...
6
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1answer
85 views
How Would A Vast Mixture (Like an Ocean) of Ammonia-Water Behave in Terms of Evaporation and Freezing?
First, I'll go ahead and say I'm not very versed in chemistry. My question comes from my interest in planetary-sciences, specifically the speculation that there are likely exoplanets and moons with ...
6
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1answer
186 views
Apparent contradiction in the type of deviation of an ethanol-water mixture
For a mixture of $\ce{EtOH}$ and $\ce{H2O}$: $\Delta H_{\text{mix}} < 0$ (exothermic) and $\Delta V_{\text{mix}} < 0$ (volume contraction). This means that the unlike interactions are stronger ...
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3answers
10k views
Can there be more solvent in a solute?
Something I know that leads to this question:
Water dissolved in ethanol.
It might sounds weird to say water as a solute. Textbooks always says that solvent is the one present in larger quantity. ...
5
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2answers
375 views
What solvent would have the fewest ions?
We know that water auto-ionizes (to a rather small extent).
My question is which solvent would have the fewest ions (or at least fewer ions than water).
I'm thinking that perhaps some kind of ...
5
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4answers
554 views
Why does the degree of dissociation change when we dilute a weak acid even though the equilibrium constant $K$ is constant?
$K$ represents the ratio of concentrations of molecules in a solution at equilibrium, which means that $Q_\mathrm{r}$ (that ratio at any given point) looks to be identical to $K$. In other words, the ...
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2answers
359 views
Decrease in temperature of a aqueous salt solution decreases conductivity
Why does the conductivity of a water solution drop as the temperature decreases?
How are these two related?
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2answers
104 views
Scientific Reason for Salt Solution Gaining Volume
A little background to this question: my mom placed a glass with salt and enough water to just cover the salt in a room to "absorb negative energy" out of the room at her office. It obviously "worked"....
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1answer
16k views
What is the solvent and what is the solute?
This question is and I am learning about mixtures, solutions, solutes, solvents, and other terms related to these words.
I know that a solute is the substance being mixed with or dissolved into the ...
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1answer
829 views
HCl/diethyl ether + Nitrogen?
Just wondering if anyone can tell me why bubbling nitrogen through a solution of $\ce{HCl}$/diethyl ether catalyst would remove said mix from my solution.
My current thought is that the $\ce{N2}$ ...
5
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1answer
77 views
Distribution coeffecient without concentrations
From what I understand about distribution coefficient is straight from my book — which does not give any practice examples — is that
$$D = \frac{C_\mathrm{A}(\text{ext})}{C_\mathrm{A}(\text{orig})}$$ ...
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2answers
12k views
Solubility in carbon tetrachloride
Which of these substances is more soluble in $\ce{CCl4}$?
$\ce{CH3F}$
$\ce{I2}$
$\ce{Na2SO4}$
$\ce{HCl}$
How do I even solve this kind of exercise?
My guess is that $\ce{CCl4}$ is ...
5
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1answer
134 views
What are appropriate techniques to ensure homogeneous solidification of an agar-based aqueous solution?
I am making a T1 weighted phantom for an MRI project. I'm trying to see if I can calculate how much a persons head heats up during an MRI scan. It consists of distilled boiling water, $\pu{7 g/L}$ ...
5
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1answer
312 views
Can acid mine drainage form acid rain?
Can acid mine drainage form acid rain?
Since normal acid rain is formed via combustion of fossil fuels, the sulphur dioxide and nitrogen dioxide are all in the gas phase, whereas in acid mines the ...
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1answer
8k views
How would using different salts in a salt bridge effect the voltage generated by a voltaic cell?
If I use a range of different nitrate solutions (e.g. calcium nitrate, iron nitrate) for the salt bridge in a voltaic cell, what effect would it have on the flow of ions in the voltaic cells?
Will ...
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3answers
791 views
Calculating the density of a saturated salt solution
Is there a way to calculate the density of a saturated salt solution from the solubility limits or does it have to be experimentally determined?
First instinct, is to add the mass of the salt to ...
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1answer
1k views
Why do some solid chemicals dissolve better in colder water?
I just discovered that some solid chemicals, such as $\ce{Na2SO4}$, dissolve better in cold water than hot water from here and would like to know if there is any particular reason as to why. Is it ...
5
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1answer
1k views
Byproducts of the neutralisation of hydrochloric acid with sodium hydroxide
Given a 1 M concentration of $\ce{HCl}$ and $\ce{NaOH}$ here are the pHs:
pH of $\ce{HCl}$: 1
pH of $\ce{NaOH}$: 13–14
and of course water has a pH of 7.
Here is a reaction that is most likely to ...
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2answers
553 views
Is there a soluble salt, or compound that when dissolved in water results in a solution with density less than pure water?
Generally water soluble salts tend to 'fit between' the molecules of water such that the volume of the resulting solution does not increase much relative to the volume and added mass of the salt. So ...
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1answer
405 views
Can a solid and liquid be miscible?
To be specific, what I mean is: is the following situation possible? At given temperature T, there are two substances, X and Y, such that pure X is a solid, pure Y is a liquid, and X and Y mix to form ...
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1answer
239 views
Is there a paper glue that is NOT dissolved by acetone?
Short version of the question: I need a spray-on glue that will stick paper to wood that isn't dissolved by acetone.
Long version: I am trying to glue paper on wood. It's a big sheet of paper and I ...
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1answer
3k views
Dissolving Tylenol Science Experiment - why is it fastest in distilled water?
My son has a science experiment for class to dissolve Tylenol (325mg acetaminophen) in 3 different solutions (125 mL volume each):
Distilled water
Vinegar (1 part white vinegar to 4 parts water)
Salt ...
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1answer
1k views
Is the density of the solution significantly different from the density of the solvent?
I am working on a mathematical model for the dissolution of coffee in water. I need to know some precise details about the effects of dissolution on the density of the mixture of the substances (that ...
5
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1answer
268 views
The partition coefficient for a chemical species across a membrane
What factors influence the partition factors across a membrane for a chemical species? Wikipedia defines the partition coefficient as:
In the physical sciences, a partition-coefficient (P) or ...
5
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1answer
71 views
Dissolving to Create a Solution with Ethanol
If at 95% Ethanol can dissolve chemical X at 1mg/1mL then theoretically if you have 500mg of chemical X you can dissolve it in 500mL of $\ce{EtOH}$ to get 1mg/mL correct?
My question is, if you have ...
5
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1answer
298 views
Standard solution and extracted solution : same concentration?
Summary :
I am currently testing how a certain type of foam adsorbs HAP, PCB and OCP, and to this end I am depositing some on the foam, then extracting it. To know how much was extracted, I need to ...
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2answers
156 views
How to estimate HCN content in a volatile mixture?
How can you accurately qualitatively and quantitatively determine the HCN in a volatile product from water?
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0answers
222 views
Why droplets of water and ethyl alcohol solution freeze weirdly? [closed]
I'm doing a project where I freeze water drops and solutions with water and ethyl alcohol. It's a phenomena where drops create a conical shape at the end of their freezing. But with ethyl drops, with ...
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0answers
58 views
Reference request for the number of solvents around a solute [closed]
I want to know if there is a way to find number of solvent molecules that are directly embracing a solute molecule (something like a reference or table that shows waters of hydration).
Particularly I ...
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257 views
Is it possible for an acid and base to react to form an even stronger base or acid?
Is there a combination of an acid and a base that when mixed results in a solution that is more basic or more acidic than the initial base or acid, respectively?
If so, do such combinations have a ...
4
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2answers
225 views
Finding sulfate contamination in crystallized silver nitrate
What is the best way to check for a small amount of sulfate contamination (if any) in silver nitrate? Usually, I would use dilute barium chloride to precipitate out the resulting insoluble white ...
4
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2answers
260 views
What happens if you mix two insoluble liquids but with the same density? [closed]
Would it make two separate phases? or would it make something like and emulsion?
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1answer
11k views
Deviation from Raoult's law because of adhesive and cohesive forces
A solution made of two or more compounds have adhesive and cohesive forces. Cohesive forces are the attractive forces between the same molecules. Adhesive forces are the attractive forces between ...
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2answers
13k views
Why does freezing point decrease on adding impurities?
It is a well known fact that freezing point decreases on adding impurities. I feel that it should increase on adding impurities.
Reason: I have watched this video on supercooled water. It says that ...
4
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1answer
18k views
the chemical mechanism for deviations from Raoult's law
Mixtures of ethanol and acetone have vapor pressures that are higher than predicted by Raoult's law, while mixtures of acetone and water have lower vapor pressures than predicted by Raoult's law. Why ...
