Question

Balance the following chemical equations and identify the type of chemical reaction.

$\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\to {\mathrm{MgCl}}_2\left(\mathrm{s}\right)$

Answer 1

Step 1: Given equation

$\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\to {\mathrm{MgCl}}_2\left(\mathrm{s}\right)$

Step 2: Method used for balancing the equation

Using the traditional method of balancing chemical equations. According to the method:

First, compare the total number of atoms of each element on the reactant side and the product side.

Add stoichiometric coefficients to molecules containing an element that has a different number of atoms on the reactant side and the product side.

The coefficient must balance the number of atoms on each side.

Usually, the stoichiometric coefficients for hydrogen and oxygen atoms are assigned last.

The number of atoms of an element in one species must be obtained by multiplying the stoichiometric coefficient by the total number of atoms of that element present in 1 molecule of the species.

Repeat this process till the number of all the atoms of the reacting elements are equal on both the reactant and product sides.

Step 3: Balancing the given equation

The given equation is: $\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\to {\mathrm{MgCl}}_2\left(\mathrm{s}\right)$

Equation: $\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\to {\mathrm{MgCl}}_2\left(\mathrm{s}\right)$
Reactant Side	Product Side
1 Magnesium atom	1 Magnesium atom
2 Chlorine atoms	2 Chlorine atoms

Since the number of all the atoms of the reacting elements are equal on both the reactant and product sides are equal, the equation is balanced.

Combination Reaction

A combination reaction is a reaction in which two reactants combine to form one product.

In this reaction, magnesium combines with chloride to form magnesium chloride. Hence this reaction is a combination reaction.

Hence the balanced equation is: $\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\to {\mathrm{MgCl}}_2\left(\mathrm{s}\right)$ and it is a combination reaction.