# Solubility

Discussion in 'MCAT Study Question Q&A' started by DeathandTaxes, May 16, 2014.

1. ### DeathandTaxes 5+ Year Member

104
19
Jan 29, 2012
An aqueous solution was prepared by mixing 70 grams of sugar (C12H12O11) into 100 grams of water. The solution has a boiling point of 101.11 and Kb = 0.512, what is the molar mass of the solute?

The answer is 322.58, but I don't understand why we can't just do (12*12 + 12 + 11*16) since they give us the molecular formula.

3. ### CzarcasmHakuna matata, no worries. 2+ Year Member

966
405
Jun 22, 2013
Crypts of Lieberkühn
Lol, I thought the same. Stupid question.

4. ### Hadi7183 2+ Year Member

63
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Dec 8, 2013
NWT
The main purpose of those extra pieces of information is just to distract you. This is actually a common bait in the MCAT. In this case, it was too obvious that you don't need those information to answer the question, but in more complex questions this trick can easily hunt you.

5. ### DeathandTaxes 5+ Year Member

104
19
Jan 29, 2012
Hadi, if you use the molecular formula you actually get something greater than 322. So the extra pieces of information were necessary to solving the problem

This was from Kaplan's General Chemistry review btw.

6. ### DrknoSDN

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104
Feb 21, 2014
... How do you figure?

12*12 = 144
16*11 = 176
1*12=12
144+176+12=332.