Question

If a gas is moved from a large container to a small container but its temperature and number of moles remain the same, what would happen to the pressure of the gas?
It would increase
It would be halved
It would stay the same
It would slightly decrease

Answer 1

To solve this we assume that the gas is an ideal gas. Then, we can use the ideal gas equation which is expressed as PV = nRT. At a constant temperature and number of moles of the gas the product of PV is equal to some constant. At another set of condition of temperature, the constant is still the same. Calculations are as follows:

 

P1V1 =P2V2

P2 = P1V1/V2

The correct answer is the first option. Pressure would increase. This can be seen from the equation above where V2 is indirectly proportional to P2.

Answer 2

Answer:

It would increase.

Explanation:

If the gas is moving from a larger container to a small container, the volume of the gas will decrease because the gas molecules fulfill the volume of the container they are.

With no change at the temperature and the number of moles, the process can be studied by Boyle's equation:

P1*V1 = P2*V2

Where P is the pressure, V is the volume, 1 represents the first container, and 2 the second container.

We can observe that, if the volume decreases, the pressure must increase, so equality will be true. Pressure and volume are indirectly proportional.