[xeadgbex]

These were the three questions I missed on an assignment. I'd just like to know how to do them and what the answers are.
Thank you!

Q1: What is the molarity of 35.0 mL of 8.00 M H2SO4 diluted to 0.500 L?

Q2: How many moles of solute are present in 80.0 g of an aqueous solution that is 1.70% sucrose (C12H22O11) by mass?

Q3 Calculate the mass of propylene glycol (C3H8O2) that must be added to 0.360 kg of water to reduce the vapor pressure by 2.87 torr at 40 degreesC. (P:H2O at 40 degreesC = 55.3 torr).

[Fridushka]

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[xeadgbex]

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show some work at least!

My apologies,

I hope you can assist me this is how I worked the problem
The main one I care about is the last one. Its something I need to know later on. This is what I did:

I used Raoults Law
P=molfraction x initialP
(55.3torr - 2.87torr) = molfraction x 55.3torr

molfraction = 0.948

0.948 = molsH2O/totalmols

mols H2O= 360 g
360/18.02 g/mol=20

so...
0.948 = 20/20+molsolute

molsolute=1.05 converted into grams that gives...


1.38*10^-2

Which is incorrect however I do not know why or what the correct answer would have been.

Thanks.