Question

What is the stoichiometric coefficient of $Ca$ in the following reaction?

$Ca+A{l}^{3+}\to C{a}^{2+}+Al$

• A. $1$
• B. $1.5$
• C. $2$
• D. $3$

Answer 1

Answer: (D)

$3$

Explanation:

The given reaction is a type of redox reaction.

Redox reaction is defined as the reaction in which oxidation and reduction reaction occur simultaneously.

Oxidation reaction is defined as the reaction in which an atom loses its electrons. The oxidation number of the atom gets increased during this reaction.

$Ca\to C{a}^{2+}+2e^{-}$ (x 3) ------------ eq 1

Reduction reaction is defined as the reaction in which an atom gains electrons. The oxidation number of the atom gets reduced during this reaction.

$A{l}^{3+}+3e^{-}\to Al$ (x 2) ------------ eq 2

Cancelling the electrons from both the sides, we get the equation:

$3Ca+2A{l}^{3+}\to 3C{a}^{2+}+2Al$

Hence, the stoichiometric coefficient of Ca in the given reaction is 3.

Option D is the correct answer.