Chapter 23, Problem 90A

Interpretation Introduction

Interpretation: To identify the atoms that are oxidized and reduced in the given chemical reaction.

Concept Introduction: An atom is said to be oxidized when it loses hydrogen and gains oxygen. Similarly, when an atom gains hydrogen and loses oxygen then such atoms are said to be reduced.

Answer to Problem 90A

  ${\text{NaBH}}_{\text{4}}$ is oxidized by gaining oxygen and water molecule is reduced by losing oxygen.

Explanation of Solution

From the reaction, it is clear that hydrogen ${\text{NaBH}}_{\text{4}}$ is replaced with oxygen in the product ${\text{NaBO}}_{\text{2}}$ . Similarly, there are two hydrogens in the water molecule on the reactant side and four hydrogens on the product side, this clearly shows that there is a gain of hydrogens and loss of oxygen which is called reduction. Hence, the water molecule is reduced in the reaction.

Conclusion

The reaction in which both oxidation and reduction take place simultaneously is called a redox reaction. The compound that gets oxidized and reduced solely depends on the gain and loss of electrons or on the gain and loss of oxygens during the course of the reaction.