Question

Butane is a gas at room temperature and pressure, but the butane found in some cigarette lighters is a liquid. How can this be?

Answer 1

The lighter fluid is composed of butane that normally would be a gas at standard atmospheric temperature and pressure. When it is placed in the containing body of the lighter, it is placed there under VERY HIGH PRESSURE. When hydrocarbons (alkanes) are compressed at high pressures, they undergo a phase change from gas to liquid at a certain pressure. Thus you observe the liquid. When you open the port of the lighter, the pressure forces the liquid fuel through a very tiny port, and as it emerges into the atmospheric pressure, it undergoes an immediate phase change to gas.