CDS Model Paper 4 General Knowledge

Varieties of LPG bought and sold include mixes that are primarily propane and butane, the common, mixes include propane (60%) and butane (40%), depending on the season in winter more propane, in summer more butane. Propylene and butylenes are usually also present in small concentration. A powerful odorant, ethanethiol, is added so that leaks can be detected easily.
Methane is a chemical compound with the chemical formula (CH4). Compared to other hydrocarbon fuels, burning methane produces less carbon dioxide for each unit of heat released. In many cities, methane is piped into homes for domestic heating and cooking purposes. Methane in the form of compressed natural gas is used as a vehicle fuel. Methane is used in industrial chemical processes for the production of hydrogen, methanol, acetic acid, and acetic anhydride, also used as a fuel in factories.