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

Consider a titration of potassium dichromate solution with acidified Mohr's salt solution using diphenylamine as indicator. The number of moles of Mohr's salt required per mole of dichromate is:
(The formula for Mohr's salt is FeSO4.(NH4)2SO4.6H2O)

A
6
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
4
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
3
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A 6
Mohr's saltFeSO4.(NH4)2SO4.6H2O
Dichromate will oxidise Fe2+ from Mohr's salt to Fe3+.

+6Cr2O27++2Fe2+H++3Cr3+++3Fe3+

nf=(|Change in O.S.|)×Number of atoms
nfCr2O27=|+3(+6)|×2=6
nfFe2+=|+3(+2)|×1=1

From the law of equivalence,
Equivalents of Fe2+=Equivalents of Cr2O27
nFe2+×1=1×6
nMohr's salt=nFe2+=6 mol

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