Chapter 8, Problem 8STP

Interpretation Introduction

Interpretation :

What happens when Al reacts with oxygen in air must be chosen from the given list.

Concept Introduction :

An oxidation-reduction reaction must involve change in oxidation numbers.

Aluminium reacts with oxygen to produce aluminium oxide.

Answer to Problem 8STP

Correct answer: Option C is correct.

Explanation of Solution

Reason for correct option: Option C is correct because in the reaction of aluminium with oxygen aluminium oxide is produced in which each Al atom loses 3 electrons and each oxygen atom accepts two electrons.

  $\begin{array}{l}\text{2Al}\to {\text{2Al}}^{\text{3+}}+6e\\ 3O_2+6e\to 3O^{2-}.\end{array}$

Conclusion

Reasons for incorrect options: Option A is incorrect as Al doesn’t gain electrons and O doesn’t lose electrons.

Option B is incorrect as each Al loses 3 electrons.

Option D is incorrect as each Al loses electrons and oxygen gains electrons.