The relationship between volume of a gas and temperature is given in Charles' law. It states that at constant pressure the volume of a gas is directly proportional to the temperature for a fixed amount of gas.
V/T = k
where V- volume , T - temperature and k - constant
When temperature increases, the kinetic energy of molecules too increase and the gas molecules move faster and spread out more, hence they occupy more space which means volume increases when there's an increase in temperature
