JEE Main Chemistry question

Chemistry Equilibrium JEE Main

The pH of a 0.1 molar solution of the acid HQ is 3. The value of the ionization constant, Ka of this acid is:

(A)1×10⁻³
(B)1×10⁻⁵Correct
(C)1×10⁻⁷
(D)3×10⁻¹

Answer: (B)

Solution

[H⁺]=10⁻³; Ka≈(10⁻³)²/0.1=10⁻⁵.

Question ID VK-136394