Question

If the base-dissociation constant, Kb, for a substance is 4.3 x 10^–10, what does this tell you about Ka?

Answer 1

Ka*Kb=Kw=10^-14
Ka=10^-14/(4.3*10^-10) (at 25°C)

Answer 2

Answer: The acid dissociation constant for the given substance is $2.32\times 10^{-5}$

Explanation:

To calculate the acid dissociation constant for the given base dissociation constant, we use the equation:

$K_w=K_b\times K_a$

where,

$K_w$ = Ionic product of water = $10^{-14}$

$K_a$ = Acid dissociation constant

$K_b$ Base dissociation constant = $4.3\times 10^{-10}$

Putting values in above equation, we get:

$10^{-14}=4.3\times 10^{-10}\times K_a\\\\K_a=\frac{10^{-14}}{4.3\times 10^{-10}}=0.232\times 10^{-4}=2.32\times 10^{-5}$

Hence, the acid dissociation constant for the given substance is $2.32\times 10^{-5}$