All of us are quite familiar with a cooking gas cylinder which contains in its liquefied petroleum gas, often called L.P.G. It is a mixture of different gases such as propane, butane etc. These are so highly compressed that they are in the liquefied form. When the regulator is opened; the liquid escapes from the nozzle of the cylinder into a space where pressure is very less. As a result, there is a sudden increase in volume and the liquid changes to gaseous state. The released gases get mixed with oxygen from air and ignite when burnt.
