Question

The pka of hf is 3.2 determine the pkb of hf?

Answer 1

Well, first we must remember that

`pK_(a)+pK_(b)=14`

This is because

`K_(a)*K_(b)=10^(-14)`

`-log(K_(a)*K_(b))=-log(10^(-14))\\-logK_(a)+-logK_(b)=-log(10^(-14))\\pK_(a)+pK_(b)=14`

So then

`pK_(b)=14-pK_(a)=14-3.2=1.8`

Answer 2

Answer : The value of
`pK_b` is, 10.8

Explanation :

First we have to calculate the value of
`K_a`.

The expression used for the calculation of
`pK_a` is:

`pK_a=-\log (K_a)`

Now put the value of
`pK_a` in this expression, we get:

`3.2=-\log (K_a)`

`K_a=6.3* 10^(-4)`

Now we have to calculate the value of
`K_b`.

Formula used :

`K_a* K_b=K_w`

`K_b=(K_w)/(K_a)`

Now put the value of
`K_a` in this expression, we get:

`K_b=(1* 10^(-14))/(6.3* 10^(-4))`

`K_b=1.5* 10^(-11)`

Now we have to calculate the value of
`pK_b`.

The expression used for the calculation of
`pK_b` is:

`pK_b=-\log (K_b)`

Now put the value of
`K_b` in this expression, we get:

`pK_b=-\log (1.5* 10^(-11))`

`pK_b=10.8`

Therefore, the value of
`pK_b` is, 10.8