Question

$p{K}_a$ values of two acids $A$ and $B$ are $4$ and $5$. The strengths of these two acids are related as:

• A. acid A is 10 times stronger than acid B
• B. strength of acid A : strength of acid $B=4:5$
• C. strength of two acids cannot be compared
• D. acid B is 10 times stronger than acid A

Answer 1

The correct option is A acid A is 10 times stronger than acid B

$p{K}_a=-log{K}_a$

For acid A, $K_a={10}^{-4}$ ;

Acid B, $K_a={10}^{-5}$.

Hence, A is 10 times stronger acid than B.

Option A is correct.