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Chemistry · EQUILIBRIUM
हिन्दीThe ionization constants of four weak acids are: \( \text{HF} (K_a = 3.5 \times 10^{-4}) \), \( \text{HNO}_2 (K_a = 4.5 \times 10^{-4}) \), \( \text{HCOOH} (K_a = 1.8 \times 10^{-4}) \), and \( \text{HCN} (K_a = 4.9 \times 10^{-10}) \). Which of the following gives the correct decreasing order of their acid strength?
Correct answer · Option 4
\( \text{HNO}_2 > \text{HF} > \text{HCOOH} > \text{HCN} \)
Explanation
Acid strength is directly proportional to \( K_a \). Comparing \( K_a \) values: \( \text{HNO}_2 (4.5 \times 10^{-4}) > \text{HF} (3.5 \times 10^{-4}) > \text{HCOOH} (1.8 \times 10^{-4}) > \text{HCN} (4.9 \times 10^{-10}) \).
