Home
Class 11
CHEMISTRY
Solubility product of Mg(OH)2 at ordinar...

Solubility product of Mg(OH)2 at ordinary temperature is `1.96xx10^(-11)`, pH of a saturated solution of `Mg(OH)_(2)` will be :

A

`10.50`

B

`8.47`

C

`6.94`

D

`3.47`

Text Solution

Verified by Experts

The correct Answer is:
A
`"Mg"(OH)_(2(s))hArr underset (x)(Mg^(2+)) +underset (2x) (2OH^(-))`
`K_(sp) = [Mg^(2+) ] [OH^(-)]^(2) = 1.96 xx 10^(-11) x xx (2x)^(2) =1.96 xx 10^(-11)` (concentration of solid is unity )
`4x^(3) = 1.96 xx 10^(-11)`
`x = ((1.96 xx 10^(-11))/4)^(1//3)`
`x = (4.9 xx 10^(-12))^(1//3) = 1.6 xx 10^(-4)`
So , `OH^(-)` concentration = ` 2xx 1.6 xx 10^(-4)`
i.e `[OH^(-)] = 3.2 xx 10^(-4)`
Now, pOH = `-log[OH^(-)]`
`= - log [ 3.2 xx 10^(-4)] = 4 - 0.505 = 3.495`
` :. pH = 14 - 3 . 495 = 10.505`
Promotional Banner

Similar Questions

Explore conceptually related problems

Solubility product of Ba(OH)_2 is 5.01×10^(-7) ,pOH of saturated solution of Ba(OH)_2 is

The solubility product of Mg(OH)_(2)at 25^(@)C is 1.4xx10^(-11). What is the solubility of Mg(OH)_(2) in g/L?

The solubility product of Mg(OH)_2 is 1.2 xx 10^(-11) . Calculate its solubility in 0.1 M NaOH solution.

What is the pH of a saturated solution of magnesium hydroxide, Mg(OH)_(2) at 25^(@) C)

The solubility product of Cr(OH)_(3) at 298 K is 6.0xx10^(-31) . The concentration of hydroxide ions in a saturated solution of Cr(OH)_(3) will be :

What is the pH of a saturated solution of Cu(OH)_(2) ? (K_(sp)=2.6xx10^(-19)

At 25^(@)C , the solubility product of Mg(OH)_(2) is 1.0xx10^(-11) . At which pH , will Mg^(2+) ions start precipitating in the form of Mg(OH)_(2) from a solution of 0.001 M Mg^(2+) ions ?