Question

What is true of an aqueous solution that is 15.0 percent HNO3 by mass?

A. It contains 15.0 grams of HNO3 per 1.0 liter of water.
B. It contains 15.0 grams of HNO3 per 100 grams of solution.
C. It contains 15.0 moles of HNO3 per 100 moles of water.
D. It contains 15.0 moles of HNO3 per 100 liter of solution.

Answer 1

B. It contains 15.0 grams of HNO3 per 100 grams of solution.

Step-by-step explanation:

The question asks about the mass percent of HNO3 in a solution. Mass percent is the ratio of the mass of the solute (HNO3) to the mass of the solution (HNO3 + water) multiplied by 100. A solution that is 15.0 percent HNO3 by mass means that for every 100 grams of solution, there are 15.0 grams of HNO3 and 85.0 grams of water. This ratio does not change with the volume or the moles of the solution or the solute. The only answer that matches this definition is B. It contains 15.0 grams of HNO3 per 100 grams of solution.