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1. The problem statement, all variables and given/known data[/b]

Here is the question:

-A solution was prepared by dissolving 0.46 kg of ethylene glycol (C_{2}H_{6}O_{2}) in 2.46 kg of water.

A.) calculate the molal solution

B.) calculate the expected freezing point of the solution

2. Relevant equations

m= (moles of solute)/(kg of solvent)

change (delta) T_{f}=T_{f}- T'_{f}=K_{f}(m)

3. The attempt at a solution

Question a:

atomic weights of ethylene glycol (C_{2}H_{6}O_{2}) (12 x 2) + (1 x 6) + (16 x 2) = approx 62

moles of (C_{2}H_{6}O_{2}): 46 g x (1 mol)/62 g = .742 mol

m= .742 mol/2.46 kg water = .3 mol

**** the answer to this problem is supposed to be 3 m... so how do I only get .3? What am I doing wrong? I have e-mailed and asked my teacher, but she is too busy to give me a straight answer that I understand and won't explain the steps.

Question b:

change (delta) T_{f}=T_{f}- T'_{f}=K_{f}(m)

T_{f}= 0 degrees C (since the initial solvent is water and water's freezing point is 0 degrees C)

m= 0.742 from the previous equation... if it is correct.

The problem I am having with this one is that I don't know where to get the additional information for the remaining constants. How do I know what K_{f}is? Any help would be greatly appreciated as this is due tomorrow, and my teacher has STILL not e-mailed me back :( Thanks!

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# Homework Help: Chemistry Lab equations

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