Question

For two weak acids A and B, the ratio of their percent ionisation is 4:9. The ratio of their ka would be

Answer 1

Hey mate,

● Answer-
Ka1 : Ka2 = 16 : 81

● Explaination-
# Given-
Degree of ionization for acid A = α1
Degree of ionization for acid A = α2
α1 / α2 = 4/9

# Solution-
Suppose Ka1 and Ka2 be their respective equilibrium constants.

We know that, for weak acids -
α ∝ √Ka

Therefore -
α1 / α2 = √(Ka1 / Ka2)
4 / 9 = √(Ka1 / Ka2)
Ka1 / Ka2 = 16 / 81

Therefore, ratio of Ka is 16 : 81.

Hope this is useful.
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