Question

On balancing the given redox reaction,

\[\ce{aCr2O7^2- + Bso3^2- (aq) + CH+ (aq) -> 2aCr^3+ (aq) + bSO4^2- (aq) + c(H2O(1)/2}\]

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

विकल्प

• 3, 8, 1

• 1, 8, 3

• 8, 1, 3

• 1, 3, 8

Answer 1

1, 3, 8

Explanation:

For balancing the reaction in an acidic medium, oxygen atoms are balanced by adding H₂O, whereas the H-atom is balanced by adding H⁺ ions on the opposite side. Finally, charge can be balanced by adding e⁰.

Oxidation: \[\ce{SO3^2- + H2O -> SO4^2- + 2H+ + 2e^0] x 3}\]

Reduction: \[\ce{Cr2O7^2- + 14H+ + 6e^0 -> 2Cr^3+ + 7H2O}\]

\[\ce{Cr2O7^2- + 3SO3^2- + 8H+ -> 2Cr^3+ + 3SO4^2- + 4H2O}\]

Therefore, the coefficient can be given as:

a = 1

b = 3

c = 8