<em><u>The compound hydrogen chloride has the chemical formula HCl and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride gas and hydrochloric acid are important in technology and industry. Hydrochloric acid, the aqueous solution of hydrogen chloride, is also commonly given the formula HCl.</u></em>
Temperature is a measure of the average kinetic energy of the particles in a sample of a gas.
Kinetic energy is the energy possessed by an object because of its motion. As an object absorbs heat the particles move faster so the average kinetic energy and therefore the temperature increases.
When the temperature of a body or an object is increased and hence the heat, there is more movement or vibration of particles which translates to more kinetic energy.