Question

In the following reaction, which substance is oxidized and which is reduced?
\(4\text{Na} + \text{O}_2 \rightarrow 2\text{Na}_2\text{O}\)

Hint:

In a reaction between a metal and a non-metal, the metal is almost always oxidized (loses electrons) and the non-metal is reduced (gains electrons).

Answer 1

Step 1: Understanding the Concept:
Oxidation is the gain of oxygen or loss of electrons.
Reduction is the loss of oxygen or gain of electrons.

Step 2: Detailed Explanation:
In the given reaction: \(4\text{Na} + \text{O}_2 \rightarrow 2\text{Na}_2\text{O}\)
1. Look at Sodium (\(\text{Na}\)): It starts as elemental Sodium and gains oxygen to become Sodium oxide (\(\text{Na}_2\text{O}\)). Gaining oxygen means it is oxidized.
2. Look at Oxygen (\(\text{O}_2\)): In terms of electrons, elemental Oxygen (oxidation state 0) gains electrons from Sodium to become oxide ions (\(\text{O}^{2-}\)) in \(\text{Na}_2\text{O}\). Gaining electrons means it is reduced.

Step 3: Final Answer:
Sodium is oxidized, and Oxygen is reduced.