Chemistry doubt-

Question

When the gases sulphur dioxide and hydrogen sulphide mix in the presence of water, the reaction SO2+2H2S→2H2O+3S occurs. Here hydrogen sulphide is acting as?

a) an oxidizing agent

b) a reducing agent

c) a dehydrating agent

d) a catalyst

Answer 1

SO₂ + 2H₂S ==> 2H₂O + 3S ... balanced equation

oxidation number of S in H₂S on the left is 2-

oxidation number of S in SO₂ on the left is 4+

oxidation number of S on the right is zero

So, H₂S has acted as a reducing agent (option b)