wiz-icon
MyQuestionIcon
MyQuestionIcon
2
You visited us 2 times! Enjoying our articles? Unlock Full Access!
Question

Which of the following compounds has the highest value of pKa?


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

The correct option is B II
Since,
Acidic strength1pKa
Conjugate base so formed after removal of H+ of all compounds is :

Since -I effect of chlorine stabilizes the conjugate base formed, more the chlorine atoms attached, more is the stability of conjugate base and more is the acidic nature of the compound.

In II, there is no chlorine atom attached, and CH3 attached increases the electron density through +I effect, making it the least stable. Hence, it is least acidic and will have highest pKa .
So, II has the highest value of pKa

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