A 0.1 M solution of a weak monobasic acid is 1.5% ionised. Using K_a=calpha^2/(1-alpha), calculate K_ax10^5 to two decimal places.

JEE Main levelNumerical answerDifficulty 2 of 3ie081

A $0.1 M$ solution of a weak monobasic acid is $1.5%$ ionised. Using $K_{a} = c α^{2} / (1 - α)$ , calculate $K_{a} \times 1 0^{5}$ to two decimal places.

Numerical answer type, tolerance 0.01.

K_{a} = \frac{c α ^{2}}{1 - α} = \frac{0.1 \times ( 0.015 ) ^{2}}{0.985} = 2.2843 e - 05

. So

K_{a} \times 1 0^{5} = 2.28