Question

Write the correct balanced chemical for the following reaction:
Dilute sulfuric acid reacts with aluminium powder.
(A) ${{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{(aq) + 2Al(s)}} \to {\text{A}}{{\text{l}}_{\text{2}}}{{\text{(S}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{3}}}{\text{(aq) + }}{{\text{H}}_{\text{2}}}$
(B) ${{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{(aq) + 4Al(s)}} \to {\text{2A}}{{\text{l}}_{\text{2}}}{{\text{(S}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{3}}}{\text{(aq) + 3}}{{\text{H}}_{\text{2}}}$
(C) ${\text{3}}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{(aq) + 2Al(s)}} \to {\text{A}}{{\text{l}}_{\text{2}}}{{\text{(S}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{3}}}{\text{(aq) + 3}}{{\text{H}}_{\text{2}}}$
(D) ${\text{3}}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{(aq) + Al(s)}} \to {\text{A}}{{\text{l}}_{\text{2}}}{{\text{(S}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{3}}}{\text{(aq) + 3}}{{\text{H}}_{\text{2}}}$

Answer 1

First write the correct chemical formulae of all the reactants and products. Then count the number of atoms of each element on the reactant side and on the product side. Then balance the number of atoms of each element on the reactant side and on the product side by using appropriate coefficients.

Complete step by step answer:
Dilute sulfuric acid reacts with aluminum powder to form aluminum sulphate and hydrogen gas.
Write the unbalanced chemical equation for the above reaction:
${{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{(aq) + Al(s)}} \to {\text{A}}{{\text{l}}_{\text{2}}}{{\text{(S}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{3}}}{\text{(aq) + }}{{\text{H}}_{\text{2}}}{\text{(g)}}$
On the reactant side, the number of aluminium atoms is 1. On the products side, the number of aluminium atoms is 2. To balance the number of aluminium atoms on both sides of the equation, add coefficient 2 to aluminium on the reactant side.
${{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{(aq) + 2Al(s)}} \to {\text{A}}{{\text{l}}_{\text{2}}}{{\text{(S}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{3}}}{\text{(aq) + }}{{\text{H}}_{\text{2}}}{\text{(g)}}$
On the reactant side, the number of sulphate groups is 1. On the products side, the number of sulphate groups is 3. To balance the number of sulphate groups on both sides of the equation, add coefficient 3 to sulphuric acid on the reactant side.
${\text{3}}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{(aq) + 2Al(s)}} \to {\text{A}}{{\text{l}}_{\text{2}}}{{\text{(S}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{3}}}{\text{(aq) + }}{{\text{H}}_{\text{2}}}{\text{(g)}}$
On the reactant side, the number of hydrogen atoms is 6. On the products side, the number of hydrogen atoms is 2. To balance the number of hydrogen atoms on both sides of the equation, add coefficient 3 to hydrogen on the product side.
${\text{3}}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{(aq) + 2Al(s)}} \to {\text{A}}{{\text{l}}_{\text{2}}}{{\text{(S}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{3}}}{\text{(aq) + 3}}{{\text{H}}_{\text{2}}}{\text{(g)}}$
This is the correct balanced chemical equation.

Hence, the correct option is the option (C).

Note: This reaction belongs to the category of single displacement reactions. In this reaction, aluminium metal displaces hydrogen from its salt solution.