CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
Question

Which of the following solution will have a pH exactly equal to 9 ?

A
109 M HCl solution at 250C
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
2×103 M Ba(OH)2 solution at 250C
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
109 M NaOH solution at 250C
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
None of the above
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

The correct option is D None of the above
(a) 109 M HCl is a very dilute solution where water dissociation needs to be considered to calculate the total [H+] ions present in the solution.
[H+] from HCl = 109 M
[H+] from H2O = 107 M
Total [H+]=(109+107)=1.01×107 M
We know that pH=log10[H+]
pH=log10(1.01×107)=6.99.

(b) Ba(OH)2 is a strong base and in 1 liter aqueous solution 1 mol Ba(OH)2 dissociates to give 2 mol OH ions.
[OH]=4×103M[H+][OH]=1014[H+]=2.5×1012MpH=log10[H+]=log10(2.5×1012)=11.60

(c)
[OH] from H2O = 107 M
Total [OH]=(109+107)=1.01×107 M

We know that pOH=log10[OH]
pOH=log10(1.01×107)=6.99pH+pOH=14pH=146.99=7.01

Therefore none of these options are correct.

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