Question

Concentrated nitric acid used as a laboratory reagent is usually 69% by mass of nitric acid. Calculate the volume of the solution which contained 23 g of HNO₃. Density of conc. HNO₃ solution is 1.41 g cm⁻³.

Answer 1

Given: Mass % of HNO₃ = 69%

Mass of pure HNO₃ = 23 g

Density of the solution = 1.41 g/cm³

We are to calculate the volume of solution (in cm³) that contains 23 g of HNO₃.

Let the volume of the solution is V cm³.

Then,

Mass of solution = Density × Volume

= 1.41 × V

Since 69% of the mass is HNO₃.

Mass of HNO₃ = 69% of 1.41 . V

= `69/100 xx 1.41 * V`

= 0.9720

Set this equal to 23 g:

0.9729 ⋅ V = 23

V = `23/0.9729`

V = 23.64 cm³

∴ The volume of the solution is 23.64 cm³.