Alkanes are used mainly?

Step 1: Analyze the question The question asks about the main use of alkanes, which are saturated hydrocarbons with the general formula CₙH₂ₙ₊₂ (methane, ethane, propane, butane, and so on).

Step 2: Explain the concept Alkanes are obtained mainly from crude oil and natural gas. They burn readily in oxygen and release a large amount of heat:

CH₄ + 2O₂ → CO₂ + 2H₂O + heat

This is why they are used mostly as fuels:

• Methane (natural gas) is used for cooking and for generating power.
• Propane and butane make up LPG, the cooking gas used in Nigerian homes.
• Petrol, kerosene, and diesel are mixtures of alkanes used for vehicles, generators, and industry.

Step 3: Check each option

• A. Textile industry: Wrong. Textiles rely on fibres and dyes, not alkanes as a main use.
• B. Hydrogenation of oils: Wrong. Hydrogenation uses hydrogen to convert unsaturated oils (containing C=C bonds) into saturated fats, as in margarine production with a nickel catalyst. Alkanes are already saturated, so they are not what is used here.
• C. Domestic and industrial fuels: Correct. This is the primary use of alkanes.
• D. Fine chemicals: Wrong. Alkanes are fairly unreactive, so they are not mainly used as fine chemicals.

Step 4: Answer The correct option is C. as domestic and industrial fuels.

Exam tip: Remember "Alkanes = Fuels". They burn well but react poorly, so their main use is combustion. Questions about hydrogenation point to alkenes (unsaturated compounds), not alkanes.