You are instructed to make 150 ML of a 1.5 M potassium nitrate solution. What mass of solute must be measured to make the solution?

1 Answer
May 21, 2018

22.748 g

Explanation:

A 1.5 M solution contains 1.5 M of solute per litre of solution. As you only need 150 ml of solution, the number of moles of solute you require are (150/1000) x 1.5 = 0.225 moles.

The molar mass of potassium nitrate is 101.1032 g/mol. So you would need to measure out 0.225 x 101.1032 = 22.748 g of potassium nitrate solution.