Answer:- The answer is 4.76%.
Solution:- percent by mass of solution = (mass of solute/mass of solution)100
mass of solute = 50.0 g
mass of solvent = 1000 g
mass of solution = 50.0 + 1000 = 1050 g
Let's plug in the values in the formula..
percent by mass = (50.0/1050)100 = 4.76%