JAMB Chemistry 2015 Paper

Concept:Natural gas is a fossil fuel mixture of light alkanes, with methane as its dominant component.Explanation:Natural gas is obtained from underground reservoirs and consists mainly of gaseous alkanes.These alkanes include methane ($\mathrm{CH}_4$), ethane ($\mathrm{C}_2\mathrm{H}_6$), propane ($\mathrm{C}_3\mathrm{H}_8$), and butane ($\mathrm{C}_4\mathrm{H}_{10}$).Methane is the simplest and lightest member of the alkane family.It makes up approximately $70\%$ to $90\%$ of natural gas by volume.The other alkanes occur only in small amounts as minor components.Because of its overwhelming abundance, methane is the principal and most commercially important constituent of natural gas.Therefore, among the options given, methane is the correct answer.Answer:A. Methane ($\mathrm{CH}_4$)