2 SO32- + 4 Br- + 3 H2O 2 Br2 + S2O32- + 6 OH- In the above redox reaction, use oxidation numbers to identify the element oxidized, the element reduced, the oxidizing agent and the reducing agent.

Answer 1

Oxidation is the loss of electrons and thus the atom becomes more positive; whereas reduction is the gain of electrons and becomes more negative (i.e. less positive). Think in terms of the number line in math.

Br1- goes to Br0, so it is oxidized and is therefore being oxidized. It is a reducing agent.

Sulfur goes from an oxidation number of 4+ to an oxidation number of 2+, so it is reduced and is an oxidizing agent.