Gold (au) goes from an oxidation number of +3 to 0 in the reaction below. 2Au3+ + 6I- ---> 2Au + 3I2. what describes the Au3+ ion?
In a reduction-oxidation or better known as REDOX reaction, the substance that reduces the oxidation state is known as the substance that is REDUCED. It serves as the oxidizing agent. Thus, Au3+ in this number is considered as the oxidizing agent.