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

Consider an acidic buffer solution of acetic acid and sodium acetate at 25oC. What should be the ratio of concentration of sodium acetate and acetic acid so that pH=4 is obtained ?

Given :Ka value of acetic acid is 1.8×105 and 10(0.75)=0.18

A
0.18:1
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
1:0.18
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
1:1.81
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
None of the above
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A 0.18:1
Given, Ka(acetic acid)=1.8×105 at 25oC, pKa=log10[1.8×105]pKa=5log 1.8pKa=50.25pKa=4.75 Given , pH=4
Formula of pH for an acidic buffer solution is :
pH=pKa+log[anion of salt][acid]
4=4.75+log[sodium acetate][acetic acid]
0.75=log[sodium acetate][acetic acid][sodium acetate][acetic acid]=10(0.75)
[sodium acetate][acetic acid]=0.18
So, by mixing sodium acetate and acetic acid in the ratio 0.18:1.
The buffer of pH=4 is obtained.

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