Question

please explain your answer. I already know that the answer is E, but I want clear explination.

Given the following values of Ka and Kb at 25°C, which species is the strongest base in aqueous solutions?

Pyridine, C5H5N (Kb = 1.7× 10−9)

Acetic acid, CH3COOH (Ka = 1.8 × 10−5)

Hydrazine, H2NNH2 (Kb = 1.3 × 10−6 ) Hydrogen cyanide, HCN (Ka = 4.9 × 10−10)

A. C5H5N

B. CH3COO−

C. H2NNH2

D. NO3 −

E. CN−

Answer 1