Question

(a) What is a balanced chemical equation? Why should chemical equations be balanced?
[2 Marks]
(b) Balance the following chemical equations and identify the type of chemical reaction.
(i) $\text{Na(s)}+\text{S(s)}\stackrel{\text{Fuse}}{\to }{\text{Na}}_2\text{S(s)}$
(ii) ${\text{TiCl}}_4\text{(l)}+\text{Mg(s)}\to \text{Ti(s)}+{\text{MgCl}}_2\text{(s)}$
[2 Marks]

Answer 1

A reaction which has an equal number of atoms of all the elements on both sides of the chemical equation is called a balanced chemical equation.
[1 Mark]
Chemical equations must be balanced because every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed.
[1 Mark]
(b)
(i) $2\text{Na(s)}+\text{S(s)}\stackrel{\text{Fuse}}{\to }{\text{Na}}_2\text{S(s)}$; Combination reaction
[1 Mark]
(ii) ${\text{TiCl}}_4\text{(l)}+2\text{Mg(s)}\to \text{Ti(s)}+2{\text{MgCl}}_2\text{(s)}$; Displacement reaction
[1 Mark]