Calculate the concentration of nitric acid in moles per litre in a sample which has a density, 1.41 g `mL^(–1)` and the mass per cent of nitric acid in it being 69%.

Explanation

The given sample is 69%, i.e., 100 g of the solution contain only 69 g of nitric acid. Molar mass of nitric acid (`HNO_3) = 1 + 14 + (3 xx 16) = 63 g mol^(-1)`
`therefore` Number of moles in 69 g nitric acid (100 g of the solution) `=69/63 =1.095`
Volume of 100 g of `HNO_(3)` solution `=("mass")/("density") = 100/1.41`
=70.92 mL = 0.07092 L
Hence, concentration of nitric acid solution = `1.095/(0.07092) = 15.44` moles/L
=15.44 M