Question

calculate the concentration of nitric acid in moles per litre in a sample which has a density 1.41 gram per ml and mass % of nitric acid in 69%​

Answer 1

Mass percent of 69% means tat 100g of nitric acid solution contain 69 g of nitric acid by mass.

Molar mass of nitric acid (HNO3) = 1+14+48 = 63g mol-1

Number of moles in 69 g of HNO3 = 69/63 moles = 1.095 moles

Volume of 100g nitric acid solution = 100/1.41 mL = 70.92 mL = 0.07092 L

∴ Conc. of HNO3 in moles per litre = 1.095/0.07092 = 15.44 M