Question

Write the chemical formulae and hence balance the following word equation

iron+chlorine$\stackrel{∆}{\to }$ferric chloride

Answer 1

Balanced chemical equation: A balanced chemical equation represents an equation in which the number of atoms of each element is equal on both the reactant and product sides.

Conversion of name reaction to the chemical equation:

Name reaction: Iron+Chlorine$\stackrel{∆}{\to }$Ferric chloride

Chemical equation: $\underset{\mathrm{Iron}}{\mathrm{Fe}}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2}\to \underset{\mathrm{Ferric}\mathrm{chloride}}{{\mathrm{FeCl}}_3}$

Balancing of given reaction:

Step 1: Calculating the number of atoms on both sides of the reaction

$\underset{\mathrm{Iron}}{\mathrm{Fe}}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2}\to \underset{\mathrm{Ferric}\mathrm{chloride}}{{\mathrm{FeCl}}_3}$

Elements	Number of atoms on the reactant side	Number of atoms on the product side
$\mathrm{Fe}$	1	1
$\mathrm{Cl}$	2	3

Step 2: Balancing the uneven number of atoms on the reactants and product side

• As the atoms of each element are not equal on both sides of the reaction we need to add stoichiometric coefficients to balance each element
• To balance the chlorine we multiply the product side with ‘2’
• To balance the chlorine and iron we multiply the reactant side with ‘2’ & ‘3’ respectively.

The equation becomes: $\underset{\mathrm{Iron}}{2\mathrm{Fe}}+\underset{\mathrm{Chlorine}}{3{\mathrm{Cl}}_2}\to \underset{\mathrm{Ferric}\mathrm{chloride}}{2{\mathrm{FeCl}}_3}$

Elements	Number of atoms on the reactant side	Number of atoms on the product side
$\mathrm{Fe}$	2	2
$\mathrm{Cl}$	6	6

The final balanced reaction is : $\underset{\mathrm{Iron}}{2\mathrm{Fe}}+\underset{\mathrm{Chlorine}}{3{\mathrm{Cl}}_2}\to \underset{\mathrm{Ferric}\mathrm{chloride}}{2{\mathrm{FeCl}}_3}$