Question

On balancing the given redox reaction,

\(aCr_2O_7^{2-} + bSO_3^{2-} (aq) + cH^+(aq) \to 2aCr^{3+}(aq) + bSO_4^{2-}(aq) + \frac c2 H_2O(\ell)\)

the coefficients a, b and c are found to be, respectively-

(1) 3, 8, 1

(2) 1, 8, 3

(3) 8, 1, 3

(4) 1, 3, 8

Answer 1

Correct option is (4) 1, 3, 8

Reaction has to be balanced in acidic medium 'O' atoms are balanced by adding H₂O and then H-atom is balanced by adding H' ions and charge is balanced by e\(^\Theta\).

a = 1

b = 3

c = 8