Question

If number of gas molecules in a cubical vessel is increased from N to 3N, then its pressure and total energy will become

• A. four times
• B. three times
• C. double
• D. half

Answer 1

The correct option is B three times

For an ideal gas $P\times V=N\times K\times T$
where P is the pressure, V is volume of the cubical vessel,
N is no. of molecules, K Boltzmann's constant and T is temperature
So as N increases to 3N, pressure also increases by three times.
And the total energy for an ideal gas $E=\frac{3}{2}\times N\times K\times T$
Hence the total energy also increases by three times.