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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Diffused Layer ion in Electrix Double Layer
When KI is added to AgNO3 soln, so AgNO3 is in excess, collidal particle is AgI:Ag+ with diffused layer of I-, Why is the diffused layer not of NO3- when the anion in excess is NO3-?
If we had KI in ...
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1answer
3k views
Boiling point elevation for a mixture of ethanol and water
Properties such as boiling point, freezing point and vapour pressure
of a pure solvent change when solute molecules are added to get
homogeneous solution. These are called colligative properties.
...
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1answer
766 views
Finding the mole fraction
At $25\ \mathrm{^\circ C}$ the vapor in equilibrium with a solution containing carbon disulfide and acetonitrile has a total pressure of $263\ \mathrm{torr}$ and is $85.5\ \mathrm{mol}\text{-}\%$ ...
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1answer
2k views
How to calculate the new concentration of a solution after adding more solute and convert it to ppm?
My question is the following:
$2~\mathrm{g}$ table salt is added to $0.5~\mathrm{m^3}$ water whose salt concentration is $10~\mathrm{mg\,L^{-1}}$. Compute the salt concentration of the mixture in ...
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0answers
383 views
What happens to the attraction of glycerol to a positively charged acetate rod if water is added
I know that glycerol is more polar than water because it has stronger intermolecular forces and its also more viscous. If I were to add water to a glycerol solution, would the solution get less polar ...
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77 views
How to quantify the amount of paracetamol present
What is the most accurate way of determining the number of moles of paracetamol from a solution, mixed with acid or base?
I do not have access to more advanced laboratory methods like liquid ...
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0answers
25 views
How to sequester Na+ which prohibits the formation of a micro-emulsion in solution
I am mixing alkaline solutions ($\ce{Na2CO3}$) with crude oil containing carboxylic acids to create micro-emulsions. The carboxylic acids react with the alkaline moieties to create an in-situ ...
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2answers
5k views
What is the difference between reacting and dissolving?
When one chemical is added to another how would we come to know whether the compound dissolves in it or reacts with it? For example $\ce{AgNO3}$ dissolves in $\ce{CCl4}$ whereas it could also have ...
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447 views
acids, bases, salts, etc
All the chemical compounds can be categorized as acids, bases, and neutral compounds.
There are different theories, namely Arrhenius Theory, Brønsted-Lowry Theory, Lewis Theory, which define the acids ...
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1answer
7k views
Mixing polar and non polar substances [duplicate]
According to the theory of London dispersion forces, intermolecular forces are created in non polar substances by induction of instantaneous dipole to neighbouring molecules. If that is the case then ...
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1answer
410 views
How much water has boiled off when precipitation begins? [closed]
Here's a challenge problem I created! None of my students could get it; can you?
$25$ grams of table salt (NaCl) is dissolved in $150$ grams of water. The temperature of the solution is raised to its ...
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1answer
101 views
Can the ions of dissolved salts be physically separated with a strong enough external electric field?
Say you had a arbitrary amount of sodium chloride dissolved in water. Could an external electric field (e.g. the electrically charged plates in Millikan's oil drop experiment) physically pull apart ...
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2answers
350 views
how are colloids and suspensions solutions?
my definition of solution is a homogenous mixture of a solute and solvent.
and in my textbook they call colloids and suspensions solutions . how is this possible if both of them are heterogenous ...
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1answer
534 views
Find the molarity of the filtrate
I can't figure out this stoichiometry question!
10.0 mL of 1.15M copper(II) nitrate reacted with 20.0 mL of .85M ammonium hydroxide. The solution is filtered. Determine the molarity of the filtrate.
...
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2answers
776 views
How to dissolve cat hair without effecting fabric?
I am wondering if it is possible to create some sort of a solution that will dissolve cat hair (or dog hair), but, is not harmful to the surrounding fabric? I am picturing a solution you would soak a ...
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1answer
106 views
I need help finding several immiscible liquids [closed]
I am trying to fill a vial with as many immiscible liquids as possible so that they form many separate layers. I want to do this as a way to visualise how liquids with different refractive indexes ...
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1answer
81 views
Can compounds dissolved in different miscible solvents react?
For example, can crystal iodine dissolved in ethanol react with sodium thiosulfate dissolved in water when mixed together?
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2answers
802 views
Phenolphthalein Indicator mixed with base that first turns pink and then clear
What occurs in the following situation: After adding 2 drops of Phenolphthalein Indicator (an indicator that turns bases pink and stays clear for acids,) into a unknown solution, the solution turns ...
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1answer
955 views
Methyl Orange Indicator-Reason for small amount of NaOH [closed]
I used methyl orange as my indicator to titrate a weak acid:
At first, I added 3 drops of methyl orange to a solution of the weak acid, $\ce{CH3COOH}$, and the solution turned red. Then, after adding ...
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2answers
88 views
Wouldn't adding a proton acceptor still make a solution just as acidic?
Say if you add NH3 to a solution, and it accepts a proton, it still becomes NH4+ in a solution, which is also acidic. A base should decrease the hydrogen ion concentration in a solution, but how does ...
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1answer
305 views
Doesn't Ostwald's law of dilution contradict Le Chatelier's principle?
By Le Chatelier's principle, increasing the concentration of a weak electrolyte brings out more ions.
By Ostwald's dilution law, increasing the concentration of a weak electrolyte brings out less ...
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3answers
30k views
Chemical Reaction of aluminum foil in CuCl2 solution
In class we did a lab in which we first dissolved copper(II) chloride powder in water to form a blue solution. We then placed a crumbled up piece of aluminum foil in that solution. It turned brown ...
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2answers
618 views
Calculate pH of a mixture of a strong base and acid. Knowing only the pH, wt/v%, and volume of both solution. [closed]
Title explains all. I have been stuck on this for an hour and for some reason cannot understand it. I have tried to do an ICE table but get stuck halfway as I do not know whether I would use the w/v ...
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1answer
1k views
How many grams of CuSO4*5H2O yield 10 grams of H2O?
If I want there to be 10.00 g of water in the copper (II) sulphate pentahydrate sample that I'm measuring, what mass of the substance will I need in order to have 10.00 g of water?
I solved this ...
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1answer
4k views
What actually happens when citric acid is added to a highly alkaline soap solution?
A few days ago I made an experiment. I diluted a few small chunks of bar soap with 20 ml of water. I then measured the ph of the solution which was around 10. I then added a tiny amount of citric acid....
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2answers
70 views
Why does a proton react with water to form hydronium ion and why does that ion has an overall positive charge? [closed]
Take this is an example:
$$\ce{HCl(aq) -> H^+(aq) + Cl^-(aq)}$$
and
$$\ce{HCl(aq) + H2O -> H3O+ + Cl^-(aq)}$$
Clearly the proton latches on to the water molecule but why? Also, why does the ...
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votes
2answers
103 views
Copper anode dissolves in electrolysis of copper sulfate solution [closed]
I did an experiment with copper sulfate where you place two copper rods in an aqueous solution of copper sulfate. You apply an electric current and copper metal builds up on the cathode. I noticed ...
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1answer
64 views
How does sodium rosinate enhances lathering property? [closed]
Why don't we use sodium carbonate or sodium stearate? What does sodium rosinate contain that the other two don't?
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1answer
44 views
Difference between homogeneous and heterogeneous mixture [closed]
When i mix two equal but large number of stones it is possible (though extremely unlikely) that stone a and stone b perfectly segregate themselves into two halves or that they are uniformly ...
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1answer
309 views
Is vapour pressure a surface phenomenon?
As a fact, I know that vapour pressure doesn't depend on surface area.
Does this imply it is not a surface phenomenon also?
It shouldn't be as then it would depend on surface area of molecules and ...
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1answer
51 views
Titrations in three equibilums
You have three solutions:
0.1 M solution of a weak monovalent acid
0.1 M solution of a strong monovalent acid
0.1 M solution of a weak divalent acid
Each solution is titrated with 0.15 M NaOH. What ...
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votes
1answer
149 views
What's the identity of the crystalline solid in the following reaction? [closed]
A mixture of toluene, benzoic acid, aniline and phenol was dissolved in diethyl ether and extracted with 5% $\ce{NaHCO3}$ solution? This extract was acidified until a white crystalline compound ...
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1answer
805 views
Is it possible to detect and measure the amount of potassium sorbate used to preserve fruit juice?
In a store bought fresh orange juice that is preserved using potassium sorbate is it possible to detect the presence of potassium sorbate and also measure the amount present?
What methods of testing ...
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1answer
52 views
Can course salt melt into water [closed]
What can cause course salt to melt? If you put it on a flat surface, can it melt on its own into water? What causes this reaction to make the salt melt?
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1answer
98 views
The Definition of a Solution
Can there be more than one solute or solvent in a solution. Why? Why not? The largest component in the solution is called a solute and smallest a solvent. How is this possible when solutions contain ...
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1answer
3k views
Mole fraction of solute of a dilute solution
According to our book, when the solution is dilute, the mole fraction of solute can be given as:
X2 = molality (m) x mass of solvent (M1) / 1000
Actually it is written as:
X2 = m/(1000/M1)
How is ...
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1answer
47 views
Cross checking the fact that gas solubility decreases with temperature increase and Henry's law's validity
It is known that the solubility of gas decreases with increase in temperature which is due to the kinetic energy freeing the solute particles into the vapor phase. Henry's law states that the partial ...
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2answers
50 views
In a double displacement reaction, why don’t the two products reform after being dissolved in water? [duplicate]
Let’s say I have $\ce{AB (aq) + CD (aq) —> AD + CB}$. When AB and CD are dissolved in water, they get dissociated into their component ions. But why don’t they reform as AB and CD, if it is already ...
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1answer
42 views
What is the solubility of d-Glucose in water as a function of temperature? [closed]
I can't find solubility of d-Glucose in water as a function of temperature.
I.e. a function that can tell me that at 35 Celsius the maximum amount of d-Glucose that can be dissolved in 100g water is ...
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1answer
311 views
Is it possible to prepare a 0.1 N solution of HCl and methanol? [closed]
In my lab guide I read: "Use a $\pu{0.1 N}$ solution of methanol-chloridic acid $(9:1)$ for the anthocyanin extraction", so I tried to calculate the volume of $\ce{CH3OH}$ and $\ce{HCl}$ to prepare it,...
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votes
1answer
2k views
Calculate pH at equivalence point [closed]
Calculate the pH at the equivalence point of a titration of 62 mL of 0.1 M $\ce{CH_3NH_2}$ with 0.20 M HCl. The $\ce{K_b}=4.4\cdot10^{-4}$.
At the equivalence point, the moles of CH3NH2 equals the ...
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votes
1answer
146 views
How to keep raspberry ketone from forming crystals again after dissolving in alcohol?
I dissolved raspberry ketone 700 mg in 10 ml of 99% isopropyl alcohol. The solubility according to pub chem is 1 g/ml. After dissolving, I added room temperature water to bring the final volume to 70 ...
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votes
1answer
47 views
Molarity of a substance in a solution when more fraction is given
Mole fraction of ethanol in a solution with water is $0.040$.
What will be the molarity of ethanol in water? Density of water can be assumed to be $1\ \mathrm{g/mL}$.
This is how I tackled the ...
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3answers
709 views
How to make a pH 6.8 Tris buffer?
To preface this, I am a biologist.
I need to make a $\mathrm{pH}=6.8$, $\pu{1 M}$ Tris buffer. We have access to Tris base and Tris Hydrochloride. (Unfortunately, none of the fancy Tris compounds ...
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1answer
192 views
Ethanol in gasoline — will it evaporate?
If gasoline with 10% ethanol is stored for a few weeks, will the ethanol evaporate?
I have read that to check for ethanol in gas is to add a little water to a container; mark the level and add gas. ...
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votes
1answer
88 views
Calcium-containing acidic solution
I want to prepare an acidic solution containing Ca ions. I thought about dissolving calcium sulphate, acetate or phosphate in $\pu{2 M}$ $\ce{H2SO4}$ or $\ce{H3PO4}$ solutions, but it seems that $\ce{...
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2answers
868 views
Is it possible to prepare a solution of hydrogen sulfate in a lab? What is the procedure to do so?
I don't want a buffer solution with it, I want to know if its possible to have a solution with only $\ce{HSO4^{-}}$ ions in it.
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1answer
2k views
One volume of something
I am following some protocols for a reaction and after diluting my substrate in a solution I need to precipitate it in methanol.
For this I need to pour my solution into "one volume" of methanol-
...
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1answer
876 views
Finding the molarity of an acid in a titration
I was doing a question that asks the molarity of a 10 mL of tartaric acid that is titrated to phenolphthalein endpoint with 20 mL of 1.0 M NaOH.
I worked it out by equating the molarity of the NaOH ...
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1answer
1k views
Basicity of Acetic acid
Acetic acid is a monobasic acid as it disassociates into CH3COO$^-$ and H$^+$.
Why don't the hydrogen atoms of CH3COO$^-$ disassociate too?
