Question

What is the oxidation number of sodium in sodium amalgam?

Answer 1

Sodium amalgam, NaHg is an alloy of mercury and sodium. The term amalgam is used for alloys. Amalgams are mixtures, not compounds. So, there is no chemical combination of mercury and metal. Therefore, the oxidation state of metal in amalgam is always zero.

The oxidation state of sodium in Na(Hg) is zero because it is a fused state of sodium in mercury which is a free state. And we must know that in a free state, the oxidation state of any element is always zero.

Hence, the oxidation number of sodium in sodium amalgam is zero.