Question

An empty plastic bottle is sealed in a cool room and then moved to a very hot room. What can best be stated about the air pressure inside the bottle when the bottle reaches room temperature?
It is lower than the pressure on the outside of the bottle.
It is higher than the pressure on the outside of the bottle.
It is the same as the pressure on the outside of the bottle.
It exerts twice the force per unit area as the air pressure outside the bottle.

Answer 1

It is higher than the pressure on the outside of the bottle.

Reason: for a sealed bottle the number of moles n and (to a good approximation) the volume V are fixed, so pV = nRT implies p ∝ T. Raising the temperature increases the gas pressure inside.