According to Boyle's Law, the pressure of a gas is inversely proportional to its volume, when temperature remains constant. This means that as the volume of a gas increases, its pressure decreases.

In the given scenario, when gas flows from one container into a larger container, the volume of the gas increases. As a result, its pressure decreases. This is because the gas molecules now have more space to move around, so they collide with the container walls less frequently.