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.
979
questions
0
votes
0
answers
26
views
Vapour pressure and boiling [duplicate]
I have come across two definitions for boiling point:
It is the temperature at which a liquid gets vaporised
It is the point where vapour pressure = external pressure
How are they related? How does ...
- 39
11
votes
2
answers
163
views
Peak in beer freezing temperature plot
I left an open beer in the freezer while monitoring its temperature. The first minutes works as expected. But after the plateau, at about −8 °C, a peak appeared:
I thought it was an artefact because ...
- 181
6
votes
0
answers
303
views
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 ...
- 5,567
-4
votes
1
answer
14k
views
How much solvent do you add for a 1:20 dilution, and why is it called 1 to 20? [closed]
A 1:20 dilution implies that you take 1 part of stock solution and add 19 parts of water to get a total volume of diluted solution equal to 20 times that of the stock solution
So is ...
- 36.4k
9
votes
1
answer
3k
views
Why does Dead Sea water feel greasy?
The best explanation I found so far is this:
These salts (magnesium, potassium, sodium, etc.) are responsible for the "greasy" feel of the water.
But it doesn’t say which salts exactly are ...
CommunityBot
- 1
6
votes
2
answers
1k
views
Does Raoult's law hold for immiscible liquids?
I know that Raoult's law holds true only for a non volatile solute in a volatile solvent mixture wherein the vapour pressure of the solution gets lowered due to the addition of solute.
Now, first of ...
3
votes
1
answer
100
views
Energy required to break apart water molecules in dissociation?
I'm learning about the process of dissociation. I'm aware in dissolution that essentially three processes occur (I know I may be simplifying it, but I am in Year 11):
Solute particles break apart (...
- 35.7k
2
votes
0
answers
65
views
Can different components show different deviations from Raoult's law?
Introduction:
Raoult's law is used to calculate the partial pressures of the vapour phases of volatile components of a solution
Given that there are two components, A and B, in the liquid-liquid ...
- 73
3
votes
1
answer
197
views
Is the mole fraction used in Raoult's law calculated initially or at equilibrium?
Raoult’s law states that:
The partial pressure of any volatile constituent of a solution at a constant temperature is equal to the vapour pressure of pure constituent multiplied by the mole fraction ...
- 20.3k
2
votes
0
answers
82
views
I have tried to remove oxidation from a metal scraper using vinegar, now the metal looks and smells burnt, what went wrong?
I have recently tried to remove some oxidation from a metal scraper spatula by using vinegar. After leaving it there for a couple of hours I was left with a burnt smell (with a hint of burnt candle ...
- 5,593
3
votes
1
answer
33k
views
Can you find the mass of solvent with mass of solute, volume of solution, and solution density?
If you have, for example, $\pu{10 g}$ of a solute dissolved into $\pu{100 ml}$ of a solution, and the solution density is $\pu{1.5 g ml^-1}$, can you just multiply $100\ \mathrm{ml} \times 1.5\ \...
- 37.2k
3
votes
0
answers
258
views
while using Henry's law does it matter if the solvent is volatile or not?
I am studying about binary solutions (with liquid solvents) and came across Henry's law. This is how it's stated in my textbook:
Henry's law states that at a constant temperature the solubility of ...
-1
votes
1
answer
536
views
Heating NaOH solutions
I am trying to determine the best heat at which to use an NaOH solution to clean a textile fiber. This is being done, carefully, in Asian villages.
The raw material is ribbons of bark peeled from a ...
- 13.5k
2
votes
0
answers
219
views
Why does conductivity of a solution of sodium in liquid ammonia decrease with a decrease in temperature?
What happens to the conductivity when a solution of sodium in liquid ammonia at $\pu{-33^{\circ}C}$ (Boiling point of ammonia) is further cooled?
I expected the solution to behave as any other ...
- 2,735
2
votes
2
answers
621
views
How do you achieve phase separation of a methanol / chloroform solution?
If I'm washing a methanol solution with chloroform, can I just add water in a 1:1 mixture with the methanol and expect it to break? Do I need to do anything else to cause the aqueous phase to separate ...
- 38.5k
0
votes
1
answer
158
views
What does water saturated oxygen mean? [closed]
What does water saturated oxygen mean in this question:
The vapour pressure of water at 80º C is 355 torr. A 100 ml vessel contained water saturated oxygen at 80º C, the total gas pressure being 760 ...
- 48.3k
0
votes
1
answer
50
views
Using samples in titrations
I've never done an experiment before. So, the methodology provided in this pdf is quite confusing.
Link to the pdf: https://www.canterbury.ac.nz/media/documents/science-outreach/vitaminc_iodine.pdf
So,...
-1
votes
2
answers
577
views
Why vapor pressure is unaffected by change in atmospheric pressure [duplicate]
I am a high school student and I am very confused in a topic about "vapor pressure of liquid". Why doesn't a change in atmospheric pressure affect vapor pressure? I think intuitively that ...
- 1,442
-2
votes
1
answer
2k
views
Calculating molarity of iodine solution after reaction
I made an iodine solution referring to the methodology provided in this link:
https://www.thoughtco.com/vitamin-c-determination-by-iodine-titration-606322
$$\ce{KIO3 + 5KI + 3H2SO4->3I2 + 3H2O + ...
- 11.5k
2
votes
1
answer
200
views
Does equality of molarity or molality determine constancy of boiling (or freezing) points of different solutions?
I encountered a question among papers for JEE (2005) that demands completing a statement:
Equimolar solutions in the same solvent have _______
There are four options and the correct answers are
...
- 20.3k
10
votes
2
answers
1k
views
Can aluminium form blue-colored solution in liquid ammonia?
I've read that group 1 elements and group 2 elements with exception of Be form blue-colored solutions in liquid ammonia (Mg requires an electrolytic process). What are the conditions for a metal to ...
- 48.3k
0
votes
1
answer
481
views
is boiling point a colligative property? [closed]
I know that elevation in boiling point is a colligative property .But is elevation in boiling point a colligative property ? Boiling point should be a colligative property acc to me bcz it depends ...
- 11
1
vote
0
answers
33
views
Cleaning solution alternatives for acetate, nitrate, or polyester base motion picture film
I am in search of alternative film cleaning solutions which are safe for the film, me, and the environment.
I have used several different professional film cleaning solutions in my many years of ...
- 111
2
votes
1
answer
2k
views
Universal symbols for molar mass, molarity, and molality
This is a really basic (perhaps trivial) question, but I just want to confirm:
What are the SI symbols for molar mass, molarity, and molality? For molality and molarity, there is a difference, but I’...
CommunityBot
- 1
0
votes
2
answers
191
views
Finding freezing temperature and osmotic pressure of an ethylene glycol and glycerol solution in water
A water solution is prepared by mixing $\pu{200 g}$ of a ethylene glycol (ethan-1,2-diol; $\ce{C2H6O2}$) solution (20% by weight) with $\pu{500 g}$ of glycerol (propan-1,2,3-triol; $\ce{C3H8O3}$) ...
- 38.5k
5
votes
2
answers
9k
views
Why is partial pressure proportional to mole fraction in Henry's law?
According to Henry's law of partial pressure, partial pressure of a gas above a solution is directly proportional to the mole fraction of the gas in the solution.
But my question is: If the mole ...
- 38.5k
1
vote
1
answer
158
views
Detection of NaF levels in aqueous solution also containing NaCl
Is it possible to determine the concentration of sodium fluoride, more specifically fluoride ions, in a solution that also contains sodium chloride?
I have looked into using an ion-specific electrode, ...
1
vote
1
answer
55
views
diprotonated vs monoprotonated inorganic phosphate
We have made confounding observations in the physiology lab working with inorganic phosphate. The cell processes we study rely upon the transport of diprotonated inorganic phosphate. But we get ...
- 38.5k
9
votes
1
answer
994
views
Can sugars dissolve in liquid ammonia?
Can monosaccharides and disaccharides dissolve in liquid ammonia due to hydrogen bond formation?
My rationale is that these sugars may be able to form hydrogen bond with ammonia ($\ce{NH3}$).
- 38.5k
3
votes
1
answer
885
views
Effect of nitrobenzene on solution UV/Vis spectra
I am wondering if there is a difference in the maximum absorbed wavelength of light if nitrobenzene is added to an acidic or basic solution.
I've figured that resonance plays a part in some ...
- 475
1
vote
1
answer
204
views
Density and Viscosity for Solution: 80% Liquid Methane CH4 with Solution of 20% Gas Nitrogen N2 on Surface of Titan (the largest moon of Saturn)?
Problem:
Need to estimate the density and dynamic viscosity of such a mixed fluid: 80% Liquid Methane CH4 with solution of 20% Nitrogen Gas N2 with temperature of 94K and pressure of 1,467 hPa (the ...
- 4,328
4
votes
3
answers
130
views
How are compounds within a complicated mixture detected?
I was reading an article about an independent pharmaceutical watchdog group called Valisure which recently released a report stating that they found Benzene, a toxic substance, in many bottles of ...
- 37.3k
1
vote
2
answers
323
views
Finding the molarity of the combination of two solution reacting with each other
I have a question that gives two concentrations and asks for the mass of $\ce{HCl}$ formed by the reaction.
$$\ce{H2SO4 + NaCl ->Na2SO4 + HCl}$$
I have two concentrations:
$\pu{250 mL}$ of $\pu{4....
- 6,760
5
votes
2
answers
121
views
How to crystallize a solution of N,N-dimethylphenylalaninemethylesterhydrochloride without heating it?
I have an aqueous solution of N,N-dimethylphenylalaninemethylesterhydrochloride and I need to crystallise it as a salt. I'm afraid of increasing the temperature or the concentration of acid due to the ...
- 3,042
2
votes
2
answers
4k
views
Why are entries missing on a solubility data chart for ionic compounds? [closed]
There is a solubility chart in my college chemistry class text for "Solubility of Ionic compounds in water". I have copied and pasted image of chart below. I was surprised to find a dozen ...
- 359
3
votes
1
answer
46k
views
Calculating the molar mass of a solute from freezing point
A $\pu{4.305 g}$ sample of a nonelectrolyte is dissolved in $\pu{105 g}$ of water. The solution freezes at $\pu{-1.23^\circ C}$. Calculate the molar mass of the solute. $k_f$ for water is $\pu{1.86 C/...
- 20.3k
2
votes
2
answers
3k
views
Given the volumes: determine the pH and the final temperature of a mixture knowing only the initial pH and the temperature of the un-mixed components
I have a pretty basic question but the last time I took Chemistry was in 2007. I am studying the Navy's Nuclear study guide for their interviews and one of the question I am faced with is below.
...
- 20.3k
1
vote
1
answer
173
views
Finding pH using the -log, why does my calculation differ from the book's answer?
An aqueous solution containing 0.0020 mol/L barium hydroxide, what is the pH? I do the following: 14-(-log(0.0020))=11.3pH. The answer is 11.6.
2.0*10^-3 mol/L sodium hydroxide solution, what is the ...
- 10.5k
1
vote
1
answer
2k
views
Mass of sugar that was added to the water (Raoult's law)
Water has a vapour pressure of $15.5~\mathrm{mmHg}$ at $25~\mathrm{^\circ C}$. An unknown amount of the non-volatile sugar glucose ($\ce{C6H12O6}$) is added to $1.31~\mathrm{kg}$ of water and the ...
- 10.5k
1
vote
1
answer
422
views
How do I utilize Henry's Law Constant?
I have tried for several hours to answer this question with no luck. I believe I may be missing a couple of steps or I am not utilizing the given information properly. Nonetheless, some guidance will ...
- 10.5k
1
vote
3
answers
2k
views
Effect of pressure on solubility of salts
The volume of certain saturated solution is greater than the sum of the volumes of the water and salt from which it is made. On increasing pressure solubility of this salt
(a) Increases
(b) Decreases
(...
- 10.5k
1
vote
1
answer
599
views
Making a 10L HCl solution with 8.77% HCl in a 100 mL solution from a 16 M stock solution
How would you make 10L of HCl solution with 8.77% HCl in 100 mL from a 16M stock solution.
Here's what I have tried so far:
I put my percent HCl and got that down to match with the moles of HCl I ...
- 10.5k
1
vote
1
answer
821
views
Are my protolysis equations right?
We had the task to solve several salts in water and measure the pH value of the solution. After that we should "create" the protolysis equation and to tell about Chemical equilibrium[s].
I get some ...
- 10.5k
1
vote
1
answer
9k
views
p-value for ions in a solution?
The question in my class notes read as:
Calculate the p-value for each ion in a solution that is $2.00 \times 10^{-7}\ \mathrm{M}$ in $\ce{NaCl}$ and $5.4 \times 10^{-4}\ \mathrm{M}$ in $\ce{HCl}$....
- 10.5k
1
vote
1
answer
4k
views
Highest osmotic pressure
I’d like to ask a question and clear my misunderstanding.
Which of the following 0.01 M solutions have the highest osmotic pressure?
-$\ce{NaCl}$
-$\ce{C12H22O11}$
-$\ce{BaCl2}$
-$\ce{CO(...
- 10.5k
-5
votes
2
answers
422
views
will splitting a solution will keep the concentration values (and moles) the same? [closed]
I have this exercise from my H.W:
and I am asked: if we split the solution into 3 different containers equally -
how many moles will the solution have in each container?
will the Cl- concentration ...
4
votes
3
answers
545
views
Finding equilibrium concentrations in solution from initial reagent concentrations and equilibrium constant
We have the following reaction:
$$\ce{A + B<=>2C +D}$$
The initial concentration of $\ce{A}$ and $\ce{B}$ are $\pu{1M}$ each. $K_c$ is $\pu{1.0E8}$. Find the equilibrium concentration of $\ce{A}$...
- 20.3k
0
votes
1
answer
513
views
How many boiling points does a mixture of liquids have?
Let's say I have a mixture of two miscible liquids. I want to get the liquids by fractional/pure distillation. My textbook says a mixture boils over a range of temperatures. On the contrary, another ...
- 3,596
1
vote
1
answer
84
views
Salt solubility and solvent dissociation
A textbook, describing a qualitative test for the $\ce{Al^3+}$ cation in which you use $\ce{NH4Cl}$ and $\ce{NH4OH}$ to precipitate $\ce{Al(OH)3}$, mentioned that the solubility of this precipitate ...
- 20.3k
-2
votes
1
answer
117
views
What product is created in a zinc - nitrate reaction? [closed]
Question:
Place 2 mL of Nitric acid in a test tube and add a small piece of Zinc turning
I thought that the overall net ionic equation would be:
$$\ce{Zn + 2H+ -> Zn^2+ + H2}$$
Is this correct? ...
- 3,042