Concentrated nitric acid is 70% HNO3 by mass and has density 1.41 g mL^-1. Taking the molar mass of HNO3 as 63 g mol^-1, calculate its molarity in mol L^-1 (answer to one decimal place).

JEE Main levelNumerical answerDifficulty 2 of 3so005

Concentrated nitric acid is $70%$ $HNO X_{3}$ by mass and has density $1.41 g m L^{- 1}$ . Taking the molar mass of $HNO X_{3}$ as $63 g mo l^{- 1}$ , calculate its molarity in $mol L^{- 1}$ (answer to one decimal place).

Numerical answer type, answer in mol/L, tolerance 0.05.

Molarity

= \frac{10 \times % w / w \times d}{M} = \frac{10 \times 70 \times 1.41}{63}

. This equals

15.667

, so the molarity is

15.7 mol L^{- 1}