Question

Identify the element oxidized and the element reduced, in this chemical equation:
H3AsO4 +H2S arrow H3AsO3 +S + H2O

Identify the oxidizing agent and the reducing agent
Justify why this is a redox reaction

Answer 1

(+5) (-2) (+3) (0)
2H₃AsO₄ + 5H₂S → As₂S₃ + 2S + 8 H₂O
The oxidation state of Arsenic and Sulfur changes during the reaction. So this reaction is redox.
The oxidation state of Arsenic is lessening, so Arsenic is the oxidizing agent in this reaction.
The oxidation state of Sulfur is increasing, so Sulfur is the reducing agent in this reaction.