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:

Options

A. 3
B. 4
C. 5
D. 6

Answer

D

Explanation

The following reaction occurs:
`6Fe^(2+) + Cr_(2)O_(7)^(2-) +14H^(+) to 6Fe^(3+) + 2Cr^(3+) + 7H_(2)O` From the above equation, we find that Mohr.s salt (`FeSO_(4).(NH_(4))_(2)SO_(4).6H_(2)O`) and dichromate reacts in 6 : 1 molar ratio.