Question

find the reason of the following....
in a closed vessel the pressure of gas increase and decrease with volume

Answer 1

Answer:

In a closed vessel, the pressure of a gas increases and decreases with volume as it follows the Boyle's law.

According to the Boyle's law, the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature.

On decreasing the volume of a gas, the pressure of the gas within the vessel is found to increase.  It is because the particles will now suffer more collision with the walls of the vessel and everytime a force is exerted on them. Under such circumstances, the pressure will increase.