183) One m³ of methane (CH₄) requires 2m³ of oxygen and produces 1m³ of carbon dioxide and 2m³ of water or steam.

184) Coke oven gas is obtained by burning coke in an oven.

185) A perpetual motion machine of the first kind is __________ according to first law of thermodynamics.

186) One kg of carbon requires 8/3 kg of oxygen for its complete combustion and produces 11/3 kg of carbon dioxide gas.

187) A process, in which the gas is heated or expanded in such a way that product of its pressure and volume remains constant, is called isothermal process.