A chemical compound is heated with a mixture of sodium hydroxide and calcium oxide (soda-lime), and — Hydrocarbons Chemistry Question

💡 Solution & Explanation

This reaction is decarboxylation. When the sodium salt of a carboxylic acid is heated with soda-lime ($NaOH + CaO$), an alkane is produced containing one carbon atom less than the original carboxylic acid because the carboxyl group is removed as sodium carbonate ($Na_2CO_3$). To produce propane (3 carbons), the original acid $X$ must have 4 carbons, which is butanoic acid.