A 0.05 M solution of a weak monobasic acid has pH 3.30. Neglecting alpha against 1, the K_a of the acid is nearest to (10^-3.30=5.01x10^-4)

JEE Main levelSingle correct optionDifficulty 2 of 3ie074

A $0.05 M$ solution of a weak monobasic acid has pH 3.30. Neglecting $α$ against 1, the $K_{a}$ of the acid is nearest to ( $1 0^{- 3.30} = 5.01 \times 1 0^{- 4}$ )

K_{a} = [H X^{+}]^{2} / c = (5.01 \times 1 0^{- 4})^{2} /0.05 = 5.02 e - 06

, that is

5.0 \times 1 0^{- 6}

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