Ques. 1AIPMT 2008
If a gas expands at constant temperature, it indicates that
- kinetic energy of molecules remains the same
- number of the molecules of gas increases
- kinetic energy of molecules decreases
- pressure of the gas increases
Answer
(1) kinetic energy of molecules remains the same
Solution
As per kinetic theory, average kinetic energy of gas molecules = 32kT, i.e., it depends only on temperature.
T is constant kinetic energy of the molecules remains the same.
The number of molecules does not change, and by Boyle's law (PV = constant) the pressure decreases on expansion.
Answer: (1)
Out of syllabus