Question

Translate the following statement into chemical equation and balance the equation:

Barium chloride reacts with zinc sulphate to give zinc chloride and barium sulphate.

Answer 1

Balanced chemical equation:

A chemical equation in which the number of atoms of each element on both sides of the equation is equal is called a balanced chemical equation.

The steps for balancing a chemical equation are:

• Write down the unbalanced equation containing the correct molecular formula of all the reactants and products.
• Determine whether or not the chemical equation is already balanced.
• If the equation is not balanced, start by balancing the elements that occur in the lowest number of reactant and product molecules.
• Balance the remaining elements.
• Make sure that the number of atoms in each element is balanced.

Translation and balancing of given chemical reaction:

Step 1: Representation of the chemical reaction:

• Barium chloride reacts with zinc sulphate to give zinc chloride and barium sulphate.
• Reaction can be written as:

$\underset{\mathrm{Barium}\mathrm{chloride}}{{\mathrm{BaCl}}_2}+\underset{\mathrm{Zinc}\mathrm{sulphate}}{{\mathrm{ZnSO}}_4}\to \underset{\mathrm{Zinc}\mathrm{chloride}}{{\mathrm{ZnCl}}_2}+\underset{\mathrm{Barium}\mathrm{sulphate}}{{\mathrm{BaSO}}_4}$

Step 2: Calculating the number of atoms on both sides of the reaction:

Elements	Number of atoms on the reactant side	Number of atoms on the product side
Ba	1	1
Cl	2	2
Zn	1	1
S	1	1
O	4	4

Step 3: Balancing the uneven number of atoms on the reactants and products side:

1. As the number of atoms on the reactants and products side is the same, so the reaction is already balanced.

So, the balanced equation is:

$\underset{\mathrm{Barium}\mathrm{chloride}}{{\mathrm{BaCl}}_2}+\underset{\mathrm{Zinc}\mathrm{sulphate}}{{\mathrm{ZnSO}}_4}\to \underset{\mathrm{Zinc}\mathrm{chloride}}{{\mathrm{ZnCl}}_2}+\underset{\mathrm{Barium}\mathrm{sulphate}}{{\mathrm{BaSO}}_4}$