I need to know how to solve these chemistry questions?

Question

No answers, please. I just need to see the steps involved.

1. How many grams of SO3 (g) would be contained in 15.5L at 175kPa and 35.0˚C?

2. Calculate the boiling point of a solution containing 4.6mol of AlCl3 in 800g of water. (Kb for water = 0.512˚C/m)

3. A 0.150M solution of vinegar, CH3COOH, is only partially ionized so that the [H+] = 2.31 x 10-3M.

What is the Ka for this acid.

4. How many equivalents are in 15.0g of H3PO4?

I can learn how, but I need to see how it's done. The teacher can try to explain it all she wants, but I need to see it in order to understand it.

Answer 1

1, ideal gas equation - PV = NRT
pressure, volume, number moles, ideal gas constant, temperature in kelvin.

using this find number of moles then convert into mass by moles = mass/ molar mass

2, dunno!

3, Ka = [H+] [A-]/[A]
you know h+ and [A-] (the acid minus its proton because you assume all H+ come from A (acid)
so you can write

Ka = ([H+]^2)/[CH3COOH

4, not a clue what the question even is

Answer 2

1. Atomic weights: S=32 O=16 SO3=80

15.5LSO3 x 273K/308K x 175kPa/101kPa x 1molSO3/22.4LSO3 x 80gSO3/1molSO3 =

I'm under the impression that SO3 is a solid at these temperatures, but let that pass.

2. 4.6molAlCl3/0.8kgH2O x 4ionmol/1molAlCl3 x 0.512degC/1iomol =

The answer plus 100C is the boiling point

3. Let acetic acid be called HOAc and acetate ion OAc-

Ka = [H+][OAc-]/[HOAc]

Ka = (2.31x10^-3)(2.31x10^-3) / (1.5x10^-1)

4. Atomic weights: H=1 P=31 O=16 H3PO4=98

15gH3PO4 x 1molH3PO4/98gH3PO4 x 3eqwtH3PO4/1molH3PO4 =