Complete the following sentence:
Domestic gas cylinders like Indane contain mainly ___________.

Domestic gas cylinders like Indane contain mainly 'butane'.

Explanation

LPG is a highly flammable mixture of hydrocarbon gases, mainly composed of propane and butane. It (Liquefied Petroleum Gas) produces more heat (per unit mass) on burning because it has higher calorific value (50 kJ/g) than coal (25-30 kJ/g).