A certain weak acid has a dissociation constant `1.0xx10^(-4)`. The equilibrium constant for its reaction with a strong base is :

Options

A. `10^(-14)`
B. `10^(-9)`
C. `10^(-10)`
D. `10^(10)`

Answer

D

Explanation

`HA hArr H^(o+) = A^(Theta)`
`K_(a) =([H^(o+)][A^(Theta)])/([HA])`
`HA + NaOH rarr NaA + H_(2)O`
or
`HA + overset(Theta)OH rarr Atheta + H_(2)O`
`K_(Eq) = ([A^(Theta)][H_(2)O])/([HA][overset(Theta)OH])`
`(K_(eq))/(K_(a)) = (1)/([H^(o+)][overset(Theta)OH])=(1)/(K_(w))`
`:. K_(eq) = (K_(a))/(K_(w)) = (10^(-4))/(10^(-14)) = 10^(10)`