The K_a for HCN is 4.9 × 10^-10.What is the value of K_b for CN^-? A)2.0 × 10^-5 B)4.0 × 10^-6 C)4.9 × 10⁴ D)4.9 × 10^-24 E)2.0 × 10⁹

Question

Quizplus · Accepted Answer

The K_b for a molecule is the equilibrium constant for the reverse reaction of the molecule. To find the value of K_b for CN^-, we can use the fact that the equilibrium constant for the reverse reaction is the reciprocal of the equilibrium constant for the forward reaction. Thus, the value of K_b for CN^- is: 1 / (4.9 × 10^-10) = 2.0 × 10^-5 Therefore, the best choice is A.

The Ka for HCN Is 4

The K_a for HCN Is 4