Question

Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in aqueous solution. What should be the molarity of such a sample of the acid if the density of the solution is 1.504 g mL^-1?

Answer 1

68% nitric acid by mass means that

Mass of nitric acid = 68 g

Mass of solution = 100 g

Molar mass of HNO₃ = 63 g mol^-1 

68 g HNO₃ = mole = 1.079 mole 

Density of solution = 1.504 g mL^-1 

Volume of solution = \(\frac{100}{1.504}\) mL = 66.5 mL = 0.0665 L