Answer:
5.66 %.
Step-by-step explanation:
mass percent is the ratio of the mass of the solute to the mass of the solution multiplied by 100.
mass % = (mass of solute/mass of solution) x 100.
mass of potassium nitrite = 30.0 g,
mass of the solution = mass of water + mass of potassium nitrite = 500.0 g + 30.0 g = 530.0 g.
∴ mass % = (mass of solute/mass of solution) x 100 = (30.0 g/530.0 g) x 100 = 5.66 %.