The mass percent of a solution that has 0.50 mol of NaOH in 100 g of solution is 5.0%.

Question

Quizplus · Accepted Answer

The mass percent of a solution is calculated by dividing the mass of the solute by the total mass of the solution and multiplying by 100.

In this case, we have 0.50 mol of NaOH. To find the mass of NaOH, we need to know its molar mass, which is 23 + 16 + 1 = 40 g/mol. Therefore, the mass of 0.50 mol of NaOH is 0.50 mol x 40 g/mol = 20 g.

The total mass of the solution is given as 100 g.

Mass percent of NaOH = (mass of NaOH / total mass of solution) x 100
= (20 g / 100 g) x 100
= 20%

Therefore, the correct mass percent of the solution is 20%, not 5%. Hence, Option B is correct.

The Mass Percent of a Solution That Has 0