You have a solid A with an impurity B and you would like to purify A. Your initial? mixture is 80% A and 20% B (where A and B have the same molecular weight). As often occurs in organic chemistry, both the impurity and the desired component in a solid mixture may have similar solubilities. You use methanol as the solvent to recrystallize 10 g of the initial mixture and obtain 8 g of recrystallized product.
Assuming A and B have identical solubilities in methanol at all temperatures: What is the % composition of the recrystallized product?