After recrystallization, the final weight of biphenyl is found to be 0.02 g. assume that all steps were carried out correctly, no spillages occurred, and the student lost minimal solid on the glassware or in transfers. why is the recovery so low?

Explanation:

From the source, The student recrystallized biphenyl by using benzene. Biphenyl is non polar and so is benzene. Biphenyl is very soluble in benzene at low as well as high temperature. Thus, it do not recrystallize as like dissolves like and gives a very poor yield.

The good recovery of the product is dependent on compound having high solubility at the high temperatures and having low solubility at the low temperatures.

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

i believe it is c.) 1575 j.