wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Given the solubility product of Cr(OH)2 as 2.0×1016 at 25 C. Calculate the minimum pH when Cr2+ ions start precipitating in the form of Cr(OH)2 from a solution having 2×104 M Cr2+ concentration ?

A
4
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
9
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
8
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
10
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 8
The equilibrium is established between undissolved Cr(OH)2 and its ions. The equilibrium established will be,
Cr(OH)2(s)Cr2+(aq)+2OH(aq)
Ksp=2.0×1016Ksp=[Cr2+][OH]2
2.0×1016=[2×104][OH]2
[OH]2=1×1012[OH]=1×106
pOH=log[OH]
pOH=6
We know that,
pH+pOH=14 at 25oC
pH=146=8

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon