Question

What is the ionization constant at 25 °C for the weak acid CH₃NH₃⁺, the conjugate acid of the weak base CH₃NH₂, Kb = 4.4 × 10⁻⁴.

a) 2.2 × 10⁻⁴
b) 4.4 × 10⁻⁴
c) 8.8 × 10⁻⁴
d) 1.1 × 10⁻⁴

Answer 1

The ionization constant at 25 °C for the weak acid (CH₃)2NH₂+, the conjugate acid of the weak base (CH₃)2NH, is 1.7 × 10^-11. None of the above options are correct.

Step-by-step explanation:

The ionization constant at 25 °C for the weak acid (CH₃)2NH+, the conjugate acid of the weak base (CH₃)2NH, can be found by using the relationship between Kb and Ka. Since Kb and Kw are related by the equation Kw = Ka * Kb, we can rearrange this equation to solve for Ka.

Ka = Kw / Kb = (1.0 × 10^-14) / (5.9 × 10^-4) = 1.7 × 10^-11.

Therefore, the ionization constant for the weak acid (CH₃)2NH₂+ at 25 °C is 1.7 × 10^-11.