Question

The Ka of an acid is 1.3 x 10^–7. Based on the Ka and its relationship with Kw, what is the value of Kb? Use KaKb=Kw

1.3 x 10^–21
7.7 x 10^–15
1.3 x 10^–14
7.7 x 10^–8

Answer 1

The value of Kb would be 7.7x10^-8

Answer 2

Answer : The value of
`K_b` is,
`7.7* 10^(-8)`

Explanation :

As we are given :
`K_a=1.3* 10^(-7)`

As we know that,

`K_a* K_b=K_w`

where,

`K_a` = dissociation constant of an acid =
`1.3* 10^(-7)`

`K_b` = dissociation constant of a base = ?

`K_w` = dissociation constant of water =
`1* 10^(-14)`

Now put all the given values in the above expression, we get the dissociation constant of a base.

`1.3* 10^(-7)* K_b=1* 10^(-14)`

`K_b=7.7* 10^(-8)`

Therefore, the value of
`K_b` is,
`7.7* 10^(-8)`