WAEC Chemistry 2013 Paper

Concept:The average kinetic energy of gas molecules is directly proportional to the absolute temperature of the gas.Explanation:According to the kinetic theory of gases, gas molecules are in constant random motion.The average kinetic energy of these molecules depends only on the absolute temperature.This relationship is expressed as:$$\text{Average kinetic energy} \propto T$$where $T$ is the absolute temperature measured in kelvin.Density measures the mass per unit volume of the gas sample.Pressure measures the force exerted by gas molecules per unit area on the container walls.Volume measures the space occupied by the gas.None of these three quantities directly measures the average kinetic energy of individual molecules.Temperature is the only variable that gives a direct measure of the average kinetic energy of gas molecules.Answer:C. Temperature