Question

Which of the following is the strongest acid?

A. HF(KaforHFis7.2×10^-4)
B. HCN (Ka for HCN is 4.9 × 10^-10)
C. HCNO (Ka for HCNO is 2 × 10^-4)
D. H3BO3 (Ka for H3BO3 is 5.4 × 10^-10)

Answer 1

HF (Ka = 7.2 × 10⁻⁴) is the strongest acid among the options given, as the higher Ka value indicates a stronger acid.

So, the correct answer is A.

Step-by-step explanation:

The strength of an acid is indicated by its acid ionization constant, Ka. The higher the Ka value, the stronger the acid because it indicates a greater tendency for the acid to lose its proton. Comparing the given Ka values, HF (Ka = 7.2 × 10⁻⁴) is the strongest acid listed, followed by HCNO (Ka = 2 × 10⁻⁴), HCN (Ka = 4.9 × 10⁻¹⁰), and H₃BO₃ (Ka = 5.4 × 10⁻¹⁰) being the weakest among the given acids. Thus, option A, HF, is the correct answer as it has the highest Ka value, indicating it is the strongest acid among those listed.

So, the correct answer is A.