Q. What is the temperature at which the kinetic energy of 0.3 mole of helium is equal to the kinetic energy of 0.4 mole of argon at 400 K?
A) 400 K
B) 873 K
C) 533 K
D) 300 K
Explanation
(c)
Number of moles of helium = 0.3
Number of moles of argon = 0.4
We know that KE $= nRT$
KE of helium $= 0.3 \times R \times T\ \ \ \ \ \ldots(i)$
KE of argon $= 0.4 \times R \times 400\ \ \ldots(ii)$
According to question
KE of helium = KE of argon
$\ \ 0.3 \times R \times T = 0.4 \times R \times 400$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ T = 533\ K$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.