A solution is prepared by adding 7.24 grams of an unknown organic compound to 21

Question

A solution is prepared by adding 7.24 grams of an unknown organic compound to 217 g of cyclohexane. This solution freezes at 2.9 deg C. Determine the molecular mass of the compound given that the freezing point of pure cyclohexane is 6.6 deg C and its Kf is 20.0degC/m.

So far i have:

DeltaTf=(Kf)(m)
(6.6-2.9)=(20.0)(m)
m=0.185

7.24g + 217g=224.24g => 0.22424 kg

0.185 = mol/0.22424kg
mol = 0.0414884

Now I have no idea what to do, Please someone help me figure this problem out step by step? Thanks!!

Explanation / Answer

m=0.185

and in 217 gms we have 7.24 gms of solute,therefore in 1000 gms e will have 33.36 gms of solute.

now this 33.36 gms of solute refers to .185 mols.

now since 0.185 mols=33.36gms

1mol=180gms

hopefully it will help u.

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