Finding Vapor Pressure Question (Raoult's Law?)

[ArtemisFei]

Alright, so for a problem in my class, it seems I'm pretty much stuck.

10g of a certain non-volatile non-electrolyte was dissolved in 100g of water at 20.0 degrees Celcius. The V.P. was lowered from 17.535 mm Hg to 17.235 mm Hg. What is the molar mass of the solute?

Alright, now, I'm assuming that Raoult's Law is used for this equation. Since the VP was given with the solute added, I'm assuming I use 17.235 mm Hg. So that takes care of the P1°. However, what do I use to plug in for the particle pressure if I'm effectively solving for the mol ratio, and therefore the molar mass?

Do I use the other given 17.535?

Or...is this even a Raoult's Law Question at all?

[ArtemisFei]

Whoa whoa. I think I may have solved it. Go go perseverance.

So...what I did for the setup was:
17.235 = (5.55/5.55+x)(17.535)

Then I got 0.097 for the mol of the unknown and by diving that by the 10g, I got the molar mass as 103.09.

It...sounds correct. Haha.