You have 2.0 g of solid A, 100.00 mL of water (100.0 g of water), and the total mass of solid A combined with 100.00 mL of water is found to be 102.0 g. The mass percent of A in this solution is
Percent by mass (%w/w) is defined as the mass of the solute divided by the mass of the solution and all of that x 100.
(2.0/102.0)*100 = ??
Watch out for significant figures. The answer is NOT 1.96%.