Question

An experiment calls for you to use 100. mL of 0.91 M HNO3 solution. All you have available is a bottle of 5.00 M HNO3. How would you prepare the desired solution

Answer 1

Available is a 5 M/liter solution. You need 100 mL of a 0.91 M solution.

In units of moles, you need 0.91 mol/liter * 0.1 liter = 0.091 moles of HNO3

0.091 moles / (5moles/liter) = 0.0182 liters of the 5 M solution.

Take 0.0182 liters of the 5 M solution, and dilute to 100 mL = 0.1 L (add 0.1 - 0.0182 = 0.0818 L = 81.8 mL of water to this solution.