Question

26. Complete and balance the following equation:

1. $\mathrm{Mg}+\hspace{0.17em}\mathrm{HCl}$

Answer 1

Step 1: Write the skeletal chemical equation

Magnesium, $\left(\mathrm{Mg}\right)$ an active metal reacts with Hydrochloric acid, $\left(\mathrm{HCl}\right)$ to form Magnesium chloride $\left({\mathrm{MgCl}}_2\right)$, metallic salt, and Hydrogen gas $\left({\mathrm{H}}_2\right)$. The skeletal chemical equation for the reaction is as follows:

$\underset{\mathrm{Magnesium}}{\mathrm{Mg}}+\hspace{0.17em}\underset{\mathrm{Hydrochloric}\mathrm{acid}}{\mathrm{HCl}}\to \underset{\mathrm{Magnesium}\mathrm{chloride}}{{\mathrm{MgCl}}_2}+\underset{\mathrm{Hydrogen}\mathrm{gas}}{{\mathrm{H}}_2\uparrow }$

Step 2: Determine the number of atoms on both sides of the equation

For balancing the reaction, both reactants and products should be balanced on both sides. The number of atoms present on the reactant as well as product side is listed below in the table:

Reactant	Product
$\mathrm{Mg}=1$	$\mathrm{Mg}=1$
$\mathrm{H}=1$	$\mathrm{H}=2$
$\mathrm{Cl}=1$	$\mathrm{Cl}=2$

Step 3: Balance the number of Cl and H-atoms

It is clear that the reactants and products are not equal.

for balancing, the reaction multiplies, HCl on the reactant side by 2.

$\underset{\mathrm{Magnesium}}{\mathrm{Mg}}+\hspace{0.17em}2\times \left(\underset{\mathrm{Hydrochloric}\mathrm{acid}}{\mathrm{HCl}}\right)\to \underset{\mathrm{Magnesium}\mathrm{chloride}}{\mathrm{Mg}{\mathrm{Cl}}_2}+\underset{\mathrm{Hydrogen}\mathrm{gas}}{{\mathrm{H}}_2\uparrow }$

Since the number of atoms of each element on both sides of the equation is balanced. Thus, the above equation is said to be balanced.

Conclusion:

Therefore, the balanced chemical equation for the given reaction is as follows:

$\underset{\mathrm{Magnesium}}{\mathrm{Mg}}+\hspace{0.17em}\underset{\mathrm{Hydrochloric}\mathrm{acid}}{2\mathrm{HCl}}\to \underset{\mathrm{Magnesium}\mathrm{chloride}}{\mathrm{Mg}{\mathrm{Cl}}_2}+\underset{\mathrm{Hydrogen}\mathrm{gas}}{{\mathrm{H}}_2\uparrow }$