Question

Write the balanced equation for the following chemical reactions.

(a) Hydrogen + Chlorine → Hydrogen chloride

Answer 1

Balanced chemical equation: A balanced chemical equation is the representation of a chemical reaction in which the number of atoms of each element is the same on both the reactant and product sides.

Word equation to symbolic equation:

• In the given reaction, Hydrogen reacts with Chlorine to form Hydrogen chloride
• The chemical reaction can be represented as:

$\underset{\mathrm{Hydrogen}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Hydrogen}\mathrm{chloride}}{\mathrm{HCl}\left(\mathrm{g}\right)}$

Balancing the Chemical Equation:

Step 1: Write the number of atoms of each element

$\underset{\mathrm{Hydrogen}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Hydrogen}\mathrm{chloride}}{\mathrm{HCl}\left(\mathrm{g}\right)}$

Element	Reactant side	Product Side
$\mathrm{H}$	$2$	$1$
$\mathrm{Cl}$	$2$	$1$

• From the table, it is clear that the atoms of hydrogen and chlorine are not balanced.

Step 2: Balancing the unbalanced atoms

• In order to balance the equation, we will make the coefficient of $\mathrm{HCl}$ as $2$.
• Now the equation becomes

$\underset{\mathrm{Hydrogen}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Hydrogen}\mathrm{chloride}}{2\mathrm{HCl}\left(\mathrm{g}\right)}$

Element	Reactant side	Product Side
$\mathrm{H}$	$2$	$2$
$\mathrm{Cl}$	$2$	$2$

Hence, the balanced chemical equation is $\underset{\mathrm{Hydrogen}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Hydrogen}\mathrm{chloride}}{2\mathrm{HCl}\left(\mathrm{g}\right)}$