Dear Student
Cr2+ is a stronger reducing agent than Fe2+.
This can be explained on the basis of the standard electrode potential values E°(Cr3+/Cr2+ = –0.41 V) and E° (Fe3+/Fe2+ = + 0.77 V).
Thus Cr2+ is easily oxidised to Cr3+but Fe2+ cannot be as readily oxidised to Fe3+.
I hope this answer will help you.
Thanks & Regards
Yash Chourasiya