Question

2H2(g) + O2(g) → 2 H2O(g)

Three atm of hydrogen gas reacts with 1 atm oxygen gas in a closed container with rigid walls. What happened to the pressure in the vessel? Hint: count the number of gas molecules on each side of the balanced chemical reaction!


a. There is no way to tell what happened to the pressure.

b. The pressure did not change.

c. The pressure decreased.

d. The pressure increased.

Answer 1

Answer:

option c.The pressure decreased

Answer 2

The pressure will decrease

Explanation:

• As per the kinetic molecular theory and Boyle’s gas law , if the volume of gas is decreased , the pressure inside the container will decrease when the volume or area of the container is fixed. In this case , due to rigid walls , the area of container does not change.
• Also the number of gas molecules is decreasing as the conversion takes place. Therefore there are fewer gas molecules when the conversion occurs , as compared to the initial number of molecules . For the same area of container , this will cause decrease in the pressure.