Question 122 of 168
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: If the average kinetic energy of and molecules, kept in two different sized containers are same, then their temperatures will be same.
Reason R: The r.m.s. speed of and molecules are same at same temperature.
Choose the correct answer from the options given below
Show answer and solution
Answer: (C) A is true but R is false
The average kinetic energy of a gas molecule is directly proportional to its absolute temperature and is given by , where is the degree of freedom. Since both and are diatomic gases, they have the same degrees of freedom (). Therefore, if their average kinetic energies are the same, their temperatures must be the same. Thus, Assertion A is true.
The root mean square (r.m.s.) speed of a gas molecule is given by . Since the molar mass of () is different from that of (), their r.m.s. speeds will be different even at the same temperature. Thus, Reason R is false.
Therefore, A is true but R is false.
Answer: A is true but R is false
The root mean square (r.m.s.) speed of a gas molecule is given by . Since the molar mass of () is different from that of (), their r.m.s. speeds will be different even at the same temperature. Thus, Reason R is false.
Therefore, A is true but R is false.
Answer: A is true but R is false