(a) Name the chemicals required for the preparation of carbon dioxide in the laboratory.

(b) Write the balanced chemical equation for the preparation of CO₂ in the laboratory.

(c) How will you collect CO₂ gas in the laboratory?

(d) Draw a labelled diagram for the preparation of CO₂ in the laboratory.

(e) Why is sulphuric acid not used for the preparation of carbon dioxide in the laboratory?

(f) Give a chemical test for carbon dioxide.

(a) The chemicals required for the preparation of carbon dioxide in the laboratory are:

1. Marble chips (CaCO₃)
2. Dilute hydrochloric acid

(b) CaCO₃ + 2HCl ⟶ CaCl₂ + H₂O + CO₂ (g)

(c) The gas is collected by the upward displacement of air.

(d) Laboratory preparation of carbon dioxide :

(e) Dilute sulphuric acid when reacts with marble chips (CaCO₃) forms calcium sulphate. It is insoluble in water so it covers the marble chips and stops the reaction.

CaCO₃ + H₂SO₄ ⟶ CaSO₄ + H₂O + CO₂ (g)

(f) When carbon dioxide is passed through limewater, the latter turns milky and when excess of gas is passed through the solution, milkiness disappears. This test is often used to check for the presence of carbon dioxide gas.