[SimpleNectarine]

1
I've been given AgCl which for some reason dissociates in water.
Which of the following decreases the solutes solubility:
AgCl solid;
AgNO3 solution;
KCl solution;
HCl solution;
There are no concentrations or anything. I think this is supposed to be 'an easy one'.

What I got from the book, is that similar molecules make each other more soluble. So AgCl solid wouldn't work, right? Since they are the same molecules and would do the opposite of whats asked?

But I'd say that AgCl solid would make it less soluble. As solution gets more saturated, the dissociation decreases (right???). Therefore AgCl solid would make the solution more saturated. And AgCl would dissociate less.

Does 'solid' or 'solution' make a difference here?


2
Which of the following have the highest freezing point (Is this supposed to mean closest to zero or furthest? I want to think that -4 would be higher than -5 as -4 is more than -5, but I guess that's not how it works?) and highest boiling point?

NaCl solution, glucose solution, sea water, distilled water.

For some reason there are no concentrations.

From the theory I'd say that I have to calculate i (isotopic coefficient), therefore sea water would probably be the answer, since it has so many salts that would dissociate and make the isotopic coefficient higher? And the more ions and molecules are in solvent, the highest the boiling point and lower the freezing point (bigger minuses)?


3
I've been given Osmotic pressures for some solutions. C=0.1M. Which of the solutions will freeze sooner?

pi = the osmotic pressure, not sure how to type it.

pi(glucosis) < pi(urea) < pi(ethanol)

From the theory it should be glucosis? Since more pressure -> the sooner it freezes ( Or the other way around)?

[Borek]

1
I've been given AgCl which for some reason dissociates in water.

I am not sure what you mean here - it always dissolves and dissociates. Only a bit, as it is weakly soluble, but it always does, for exactly the same reasons most other salts do.

Which of the following decreases the solutes solubility:
AgCl solid;
AgNO3 solution;
KCl solution;
HCl solution;

Have you heard about a common ion effect?

Which of the following have the highest freezing point

(...)

For some reason there are no concentrations.

Lack of concentrations makes me think you are asked about the literally highest freezing point, as then the answer is trivial.

From the theory I'd say that I have to calculate i (isotopic coefficient)

Van 't Hoff factor, no idea where you got the isotopic coefficient from.

I've been given Osmotic pressures for some solutions. C=0.1M. Which of the solutions will freeze sooner?

pi = the osmotic pressure, not sure how to type it.

pi(glucosis) < pi(urea) < pi(ethanol)

From the theory it should be glucosis? Since more pressure -> the sooner it freezes ( Or the other way around)?

How does the osmotic pressure depend on the concentration of solute?

How does the freezing point depend on the concentration of solute?

I must admit this ethanol solution makes me a bit wary, I am not 100% sure there is enough information to answer the question.