A flask contains argon and chlorine in the ratio of 2:1 by mass. The temperature of the mixture is 0 27°C . The ratio of average kinetic energy per molecule of the two gases is

Since argon and chlorine both have the same temperature in the flask, the ratio of average kinetic energy (per molecule) of the two gases is 1:1

It is important to note that although the molecular masses of argon and chlorine differ, this does not affect the average kinetic energy per molecule as long as the temperature is the same. This conclusion highlights a fundamental principle of the kinetic theory: the energy depends on temperature, not the identity or size of the gas molecule.