Chapter 16, Problem 1SAQ

Which substance is being oxidized in the reaction?

$2\text{Na}(s)+{\text{Br}}_{\text{2}}(g)\to 2\text{NaBr}(s)$

a. $\text{Na}$

b. ${\text{Br}}_{\text{2}}$

c. $\text{NaBr}$

d. none of the above

Interpretation Introduction

Interpretation: Interpretation: The substance that is oxidized in the given reaction is to be determined.

$2\text{Na}\left(s\right)+{\text{Br}}_2\left(g\right)\to 2\text{NaBr}\left(s\right)$

Concept introduction:

Oxidation refers to the loss of electrons during a reaction by an atom, ion, or a molecule. It occurs when the oxidation states of the molecules increase.

The opposite of oxidation is known as reduction where there is a gain of electrons or where the oxidation states of the molecule decrease.

The reactions in which oxidation and reduction takes place simultaneously are called redox reactions.

In the redox reactions that takes place between the metal and the nonmetal, the metal is oxidized while the nonmetal is reduced.

Answer to Problem 1SAQ

Correct Answer: option (a) is correct.

Explanation of Solution

Reason for correct option:

The given redox reaction is:

$2\text{Na}\left(s\right)+{\text{Br}}_2\left(g\right)\to 2\text{NaBr}\left(s\right)$

In the above reaction, metal sodium,$\text{Na}$ reacts with $\text{Na}$ reacts with a non-metal, ${\text{Br}}_2$ to form $NaBr.$ Since, in the redox reactions between the metal and the nonmetal, the metal is oxidized while the nonmetal is reduced. Thus, in the given reaction, the metal sodium,$\text{Na}$ is oxidized and nonmetal, ${\text{Br}}_2$ is reduced. Hence, the substance that is oxidized in the given reaction is sodium,$\text{Na}$.

Reasons for incorrect options:

Option (b) is incorrect according to given reaction, ${\text{Br}}_2$ gains electrons and therefore get reduced.

Option (c) is incorrect because it is the product formed from the oxidation of $\text{Na}$ and reduction of ${\text{Br}}_2$. It neither undergoes reduction or oxidation.

Option (d) is incorrect because the option (a) is correct.

Thus, the options (a), (b), and (c) are incorrect.