What is the molarity of phosphoric acid in a 31.5% (by mass)aqueous solution?
A)0.0846 m
B)0.156 m
C)0.0390 m
D)0.0780 m
E)The density of the solution is needed to solve the problem.

Question

Quizplus · Accepted Answer

To calculate molarity, the mass of the solute (phosphoric acid) and the volume of the solution are needed. The percentage by mass gives the mass of phosphoric acid per 100 g of solution, but without the density of the solution, it's impossible to convert this mass to a volume, which is necessary to calculate molarity (moles of solute per liter of solution).

What Is the Molarity of Phosphoric Acid in a 31