Question

In the equation below, identify the reducing agent, the oxidising agent and

give reasons for your answer using oxidation numbers.
H2O2
H2O + 1/2 O2
a) H₂O₂ is the reducing agent because the oxidation number of oxygen decreases from -1 to -2.

b) H₂O₂ is the oxidising agent because the oxidation number of hydrogen increases from +1 to +2.

c) H₂O is the reducing agent because the oxidation number of oxygen decreases from 0 to -2.

d) H₂O is the oxidising agent because the oxidation number of hydrogen increases from 0 to +1.

Answer 1

H₂O₂ acts as both the reducing agent and the oxidizing agent in a disproportionation reaction where oxygen is both reduced and oxidized.

Step-by-step explanation:

In the given reaction, H₂O₂ is both the reducing agent and the oxidizing agent. This process is known as a disproportionation reaction, where the same substance undergoes both oxidation and reduction. Specifically, in this reaction, the oxidation number of oxygen goes from -1 in H₂O₂ to 0 in O₂, indicating oxidation, and from -1 in H₂O₂ to -2 in H₂O, indicating reduction. Thus, H₂O₂ serves as both the oxidizer and reducer because it loses electrons (to form O₂) and gains electrons (to form H₂O).