Question

With the help of an appropriate example, justify that some of the chemical reactions are determined by the evolution of a gas.

Give a chemical equation for the reaction involved in the above case.

Give one example of a chemical reaction characterised by the evolution of a gas.

Answer 1

When zinc granules react with dilute sulphuric acid in a flask, hydrogen gas evolves, and zinc sulphate solution is formed.

\[\ce{Zn_{(s)} + H2SO4_{(aq)} -> ZnSO4_{(aq)} + H2_{(g)}}\]