Question

The concentration in (M) of bromide ions ina

saturated solution of mercury (II) bromide, Ksp
=8.0*10-20 is?

Answer 1

Answer : The concentration in (M)of bromide ions in a saturated solution of mercury (II) bromide is,
`2.7* 10^(-7)M`

Explanation :

The solubility equilibrium reaction will be:

`HgBr_2\rightleftharpoons Hg^(2+)+2Br^(-)`

Let the molar solubility be 's'.

The expression for solubility constant for this reaction will be,

`K_(sp)=[Hg^(2+)][Br^(-)]^2`

`K_(sp)=(s)* (2s)^2`

`K_(sp)=4s^3`

Given:

`K_(sp)` =
`8.0* 10^(-20)`

Now put all the given values in the above expression, we get:

`K_(sp)=4s^3`

`8.0* 10^(-20)=4s^3`

`s=2.7* 10^(-7)M`

Therefore, the concentration in (M)of bromide ions in a saturated solution of mercury (II) bromide is,
`2.7* 10^(-7)M`