wiz-icon
MyQuestionIcon
MyQuestionIcon
3
You visited us 3 times! Enjoying our articles? Unlock Full Access!
Question

Kb for a monoacidic base whose 0.2 M solution has a pH of 9.50 is:

A
5×108
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
5×109
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
6×106
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
6×109
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 5×109
BOH B+ + OH
C 0 0
C(1α) Cα Cα

Given that, pH=9.5
pOH=149.5=4.5
We know,
pOH=log[OH]=4.5
[OH]=104.5

now, [OH]=C.α
(as α=Kb/C )
so, [OH]=Kb.C

Squaring both sides:
([OH])2=Kb.C104.5×2=Kb×0.2Kb=1090.2=5×109


flag
Suggest Corrections
thumbs-up
9
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon