The concentration of urea in a solution prepared by dissolving 16 g of urea in 20 g of H2OH2O is ________% by mass. The molar mass of urea is 60.0 g/mol. The concentration of urea in a solution prepared by dissolving 16 g of urea in 20 g of is ________% by mass. The molar mass of urea is 60.0 g/mol. 44 80 0.80 0.48 0.44