[IAmMe]

I take my classes online and so far I haven't found anyone that has been able to help me. Even my online tutors have told me I don't have enough information. I was hoping maybe someone here could help.


"Compute the freezing point of this solution:
1.00 X 10²g C10H8O6S2 (1,5-naphthalenedisulfonic acid) in 1.00 X 10²g H2O (nonionizing solute)
The freezing point of H2O is lowered 1.86C per mole of solute.
The boiling point of H2O is raised 0.512C per mole of solute."


"Calculate the osmotic pressure of this solution.
69.7 grams of a solute with a molecular mass of 2790 grams are dissolved in enough water to make 1.00 dm³ of solution at 20 C. What is the osmotic pressure of the solution?"


"Compute the boiling point of this solution:
25.5 g C7H11NO2S
(4-nitro-2-toluenesulfonoic acid dihydrate) in 1.00 X 10² g H2O (nonionizing solute)
The freezing point of H2O is lowered 1.86C per mole of solute.
The boiling point of H2O is raised 0.512C per mole of solute."


I really don't even know where to start. I should be able to get the rest of my problems if I can figure those out. Sorry if some things go over my head. I haven't worked on any of this in a good year and a half. Any help would be greatly appreciated.

[ARGOS++]

Dear IAmMe;

You have “enough” Information, but the completely wrong, because it’s also the misleading Info!

That identifies the both the Designer of the Question and the online tutor as absolutely improper teachers!

But let’s handle the Questions as theoretical ones and correct the Information as good as possible:
Both Constants for Water have the Units:   1.86 °K mole^-1 kg and 0.512 °K mole^-1 kg.
If we translate these units into words we result in:
                                      1.86   °K per (mole Solute^*) in 1.00 kg Solvent)!  and  -
                                      0.512  °K per (mole Solute^*) in 1.00 kg Solvent)!
  ^*) But that’s only true in case we would have no dissociation of the ….-sulfonic acid, as mentioned in the Questions, and that’s absolutely stupid!!!  Such is disqualifying any Teacher!

Second: At least the Sum Formula in Question 3 is also wrong, because it must be C₇H₇NO₅S !!

Let’s start by the definition of: 
                   Mole Solute per 1.00 kg Solvent  = [mole/kg Solvent] is called MolaLity!
I hope you already know how a Mole is defined, otherwise read on: "Mole (unit)”.
With this definition and your Sum Formula you should be able to calculate the MolaLities.
(Take care in Question 3 for the term “Di-Hydrate” and its meaning!)

With all this Definitions you should already be able to answer both given Questions (1 & 3) correctly, but if you think you need additional helps you may read on:

"Freezing Point Depression” and on: "Boiling Point Elevation”.

(You will see there that also “Wikipedia” is doing a Mistake in the Definition of the Constants!)
Hint on “Wiki”: Nonionizing Solute means: i = 1!

Try to do as much as possible and show us your work,   ─  and I’m sure we will help you again!
Let’s do Question 2 later.

Good Luck!
                    ARGOS⁺⁺