Which of the following order of ions is correct for increasing strength as a reducing agent? (a) Cr2+ (b) Cr3+ (c) Cr2O72-

(c) < (b) < (a)  (a) < (b) < (c)  (b) < (c) < (a)  None of these

(c) < (b) < (a)

(c) < (b) < (a)  Cr2O72- < Cr3+ < Cr2+  Smaller the oxidation state of the element in the ion, greater is the reducing nature.