Question

A student checks the air in her bicycle tires early in the morning when it is cool outside. If she measures it again later in the day when it is hotter outside, what will she most likely observe? Explain your answer in terms of kinetic-molecular theory.

Include____________.
a. The tire pressure will be higher when the temperature is higher.
b. Pressure is the result of collisions of gas molecules with the walls of the tire.
c. Temperature is a measure of the average kinetic energy of the gas molecules.
d. As temperature increases, gas molecules move more quickly and they collide with the tire walls more frequently and with more force.
e. Pressure and temperature are directly proportional.

Answer 1

She will observe that the pressure on the tire is higher.

Step-by-step explanation:

By the ideal gas law, the pressure and the temperature are directly proportional, so, if the temperature increases the pressure increases too:

PV = nRT (P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature).

The temperature is a measure of the average kinetic energy of the gas molecules, so when the temperature increases, the energy also increases, and the gas molecules will move more quickly, so they will collide more often between themselves and in the wall. Those collisions will be with more force because the velocity is higher.

So, the pressure will be higher, because it is the result of collisions of the gas molecules with the walls of the tire.