(a) 2 c6h6(l) + 15 o2(g) → 12 co2(g) + 6 h2o(l) (b) c2h3o2-(aq) + h3o+(aq) → hc2h3o2(aq) + h2o(l) (c) 4 h+(aq) + 4 co2+(aq) + o2(g) + 24 nh3(aq) → 4 co(nh3)63+(aq) + 2 h2o(l) (d) caco3(s) → cao(s) + co2(g) (e) 2 h2o2(l) → o2(g) + 2 h2o(l) the reaction in which a single species is both oxidized and reduced

The reaction (E) 2 H₂O₂ (l) → O₂ g) + 2 H₂O (l) has a single species that is both oxidized and reduced.

Explanation:

Given the reaction (E):

2 H₂O₂ (l) → O₂ g) + 2 H₂O (l)

In hydrogen peroxide, oxygen has an oxidation state of -1. We can see that the reaction is balanced.

The products of the reaction are:

O₂ (the oxidation state of the Oxygen is 0)

H₂O (the oxidation state of the Oxygen is -2)

Hence, 1 mol of Oxygen changes its oxidation state from -1 to 0 (oxidation) and 1 mol of Oxygen changes its oxidation state from -1 to -2 (reduction).

The reaction (E) has a single species that is both oxidized and reduced.