Answer
The pressure of the rigid container decreases. The density remains constant.
The pressure of the flexible container remains constant. The density increases.
Work Step by Step
Because the reaction changes every two moles of gas into one mole of gas, both containers experience fewer moles of gas. As a result, the rigid container which does not change in volume experiences a decrease in internal pressure as there are fewer molecules hitting the walls of the container. However, the pressure of the flexible container remains constant as the flexible container is able to decrease in volume to compensate for the lesser number of moles of gas.
Density is the measure of the amount of gas in a volume. Therefore, because this reaction does not change the amount of gas in the container, the rigid container's density remains constant as there is no change in volume with the rigid container. However, the flexible container experiences an increase in pressure as the flexible container would experience a decrease in volume with fewer moles of gas but the same mass.
