Question

What mass of a concentrated solution of nitric acid (68.0% HNO3 by mass) is needed to
prepare 400.0 g of a 10.0% solution of HNO3 by mass?

Answer 1

Answer:

58.8 grams.

Explanation:

First we calculate how many HNO₃ grams are there in 400.0 g of a 10.0% solution:

• Out of 100 g of a 10.0% solution, 10 g will be of HNO₃.

• 400.0 g * 10.0/100 = 40 g HNO₃

Then we calculate the mass of a 68.0% solution that would contain 40 grams of HNO₃:

• 40 g HNO₃ * 100 g Solution/68 g HNO₃ = 58.8 g