Question

The following reaction occurs in acidic solution: As(s) + ClO3-(aq) → H3AsO4(aq)+ HOCl(aq) When this equation is balanced, a correct set of coefficient is: As, ClO3-, H+

A. 4,5,5

B. 4,4,5

C. 5,5,4

D. 4,5,6

E. 5,4,5

Answer 1

Acidic solution means excess of protons. Steps to follow during balancing of an redox reaction in acidic solution are: separate the half reactions, then balanced atoms other than Oxygen and hydrogen, then add H2O to balance oxygen, then add protons to balance hydrogen, then add electrons to balance charges on both sides, then scale the reaction to cancel some terms and the add them up to get the final reaction. The correct set of coefficient is : As = 4, ClO3- = 5, and H+ = 5. Hence, A is the correct option. The detailed solution is given below: