5 mL of N HCl, 20 mL of N/2 H₂SO₄ and 30 mL of N/3 HNO₃ are mixed together and volume made to one litre . The normality of the resulting solution is

Options

(a) N/5
(b) N/10
(c) N/20
(d) N/40

Correct Answer:

N/40

Explanation:

5 mL of N HCl , 20 mL of N/2 H₂SO₄ and 30 mL of N/3 HNO₃ are mixed. Volume of resultant solution = V(T) = 1000 mL.
Since, N₁V₁ + N₂V₂ + N₃V₃ = N(T)V(T).
⇒ 5 ⨯N + 20 ⨯N/2 + 30 ⨯N/3 = N(T) ⨯ 1000.
⇒ 5⨯ N + 10 ⨯ N + 10 ⨯ N = 1000⨯ N(T)
⇒ N(T) = N/40.