Question

Assuming pressure and temperature are held constant, what happens to the volume of a non-rigid container when number of molecules in the container is doubled?

• A. The volume doubles
• B. It decreases to half its original volume
• C. The volume stays the same
• D. It increases by a factor of four
• E. Cannot be determined

Answer 1

Answer: (A)

The volume doubles

The ideal gas equation is
$PV=nRT$
At constant pressure and temperature, $V\propto n$
Thus, volume of a gas, at constant pressure and temperature is directly proportional to the number of moles of gas.
When number of molecules in the container is doubled, the number of moles in the container is doubled and the volume of the non-rigid container is also doubled .