Question

What is the pH of the 0.1% HNO3 solution?

(H-1, N-14, O-16)

Answer 1

The density of HNO₃ = 1.413 g/mL, Weight of HNO₃ for 1 mL = 1.413 g otherwise we can write as Weight of 100 % HNO₃ for 1 mL = 1.413 g

Weight of HNO₃ for 1L = 1413 g, As solution is 0.1 % the weight of HNO₃ in 0.1 % of 1L = (1413 x 0.1)/100 = 1.413 g

Number of moles present in 0.1 % of 1L HNO₃ = 1.413/63.01 = 0.0224 M

Molarity of HNO₃ solution = Number of moles of HNO₃/ Volume of solution in liters = 0.0224 M = 2.24 x 10^-2 M

P^H= -log [H⁺] = -log[2.24 x 10-2] = 2-log (2.24)= 2-0.35= 1.65