Calculate the concentration of nitric acid in moles per litre in a sample which has a density 1.4 `g*mL^(-1)` and the mass percent of nitric acid in it being 69%.

Explanation

Molecular mass of nitric acid`=1.008+14+(3xx16)=63`
`therefore`Number of moles present in 69g of `HNO_(3)=(69)/(65)=1.095`
Given, 69g mass of `HNO_(3)` is present in 100g of `HNO_(3)`.
Vol. of 100g `HNO_(3)` solution `=(100g)/(1.41g*mL^(-1))=70.92mL`
`=70.92xx10^(-3)L`
`therefore`Concentration of nitric acid `=(1.095mol)/(70.92xx10^(-3)L)`
`=15.44mol*L^(-1)`.