Dissociation constant of a weak acid is `10^(-6)` . What is the value of equilibrium constant for its reaction with strong base

Options

A. `10^(-5)`
B. 6.9
C. None
D. `10^(9)`

Answer

4

Explanation

The concerned reaction will be
`HA+OH^(-) hArr A^(-)+H_(2)O " "….(1)`
`HA hArrH^(+)+A^(-)" "K_(a)=10^(-5)" "....(2)`
`H^(+)+OH^(-)hArr H_(2)O" "Keq=(1)/(Kw)=(1)/(10^(-14))" "....(3)`
`(1)` can be obtained by adding `(2) & (3)`
`K_(eq)=Kaxx(1)/(K_(w))=10^(-5)xx(1)/(10^(-4))=10^(9)`
Hence `(4)` ans.