Chemical properties of carbon compounds sheet5-mark answer frameExplain the combustion, oxidation, addition and substitution reactions of carbon compounds, with one equation each.
How to lay out the answer. Follow the frame, then write it in your own words.
- 1 · Open in one line. Carbon compounds show four main reactions: combustion, oxidation, addition and substitution.
- 2 · Combustion. Burning in oxygen gives CO₂, water, heat and light: CH₄ + 2O₂ → CO₂ + 2H₂O + heat and light.
- 3 · Oxidation. Alkaline KMnO₄ or acidified K₂Cr₂O₇, on heating, oxidise ethanol to ethanoic acid: CH₃CH₂OH → CH₃COOH.
- 4 · Addition. Unsaturated compounds add hydrogen with a nickel catalyst: CH₂=CH₂ + H₂ → CH₃-CH₃.
- 5 · Substitution. In sunlight, chlorine replaces hydrogen: CH₄ + Cl₂ → CH₃Cl + HCl.
- 6 · Link to real life. Hydrogenation turns vegetable oil into vanaspati, and a clean blue flame on an LPG stove shows complete combustion.
- 7 · Close in one line. So the type of bond and the reagent decide which reaction a carbon compound shows.
Scoring tip: Write the condition with each equation: catalyst, sunlight or oxidising agent. Each condition can carry a mark.
