Question

Why does the pressure inside a container of gas increase if more gas is added to the container?

Answer 1

The pressure increases because the more gas you put into the container the pressure is going to rise as well, that's because the gas is being put in the container constantly which is increasing the pressure.

Answer 2

The pressure increases on addition of more gas because according to the kinetic theory of gases, more gaseous molecules will now be available to collide with each other, this increases the number of gas molecules colliding with one another. As the number of collision increases, the average kinetic energy of the entire system also increases. This leads to more gas molecules also colliding with the walls of the containing vessel thereby resulting into an increase in pressure experienced by the walls of the containing vessel.