Question

0.01 M HX (K_a = 4 × 10^–10) is diluted till the solution has pH = 6. If the new concentration is x × 10^–4 M then find x.

Answer 1

Answer is : (25)

\(\text{H}^+ = \sqrt{\text{K}_a \times \text{C}}\)

\(10^{-6} = \sqrt{4 \times 10^{-10} \times \text{C}}\)

\(10^{-12} = 4 \times 10^{-10} \times \text{C}\)

\(\text{C} = \frac{1}{4} \times 10^{-2} = 0.25 \times 10^{-2}= 25 \times 10^{-4}\)