Kinetic Theory and Gas Laws Flashcards
Students will be able to describe the principles of the Kinetic Molecular Theory and how it explains the behavior of gases. They will apply the gas laws (Boyle’s, Charles’s, and the Ideal Gas Law) to solve problems involving pressure, volume, temperature, and the number of moles of a gas. This includes interpreting the relationships between these variables and predicting the effects of changing one or more conditions on a gas.
What is the relationship between pressure and volume in Boyle’s Law for an ideal gas?
Boyle’s Law states that for a given amount of gas at a constant temperature, the pressure of the gas is inversely proportional to its volume.
Boyle’s Law can be expressed as P1V1=P2V2, where P is pressure and V is volume. As the volume decreases, pressure increases if the temperature remains constant.
According to Charles’s Law, how does the volume of a gas change when its temperature increases at constant pressure?
Charles’s Law states that the volume of a gas is directly proportional to its temperature (in kelvins) when the pressure is held constant.
Charles’s Law is mathematically expressed as V1/T1=V2/T2 where V is volume and T is the temperature in kelvins. As temperature increases, the volume of the gas increases.
Explain why increasing the temperature of a gas at constant volume increases its pressure according to the Kinetic Molecular Theory.
According to the Kinetic Molecular Theory, increasing the temperature increases the average kinetic energy of gas molecules, causing them to collide more frequently and with greater force against the walls of the container, which increases the pressure.
The pressure exerted by a gas results from collisions of molecules with the container walls. Higher temperatures result in faster-moving molecules and therefore more frequent and forceful collisions.
A gas occupies 2.5 liters at a pressure of 1 atm. If the pressure increases to 2 atm and the temperature remains constant, what will happen to the volume of the gas according to Boyle’s Law?
According to Boyle’s Law, the volume of the gas will decrease to half its original value, or 1.25 liters, because pressure and volume are inversely proportional.
Since P1V1=P2V2, doubling the pressure results in halving the volume if the temperature remains constant.
Using the Ideal Gas Law, explain what would happen to the pressure of a gas if the volume is halved and the temperature is doubled, assuming the amount of gas remains constant.
According to the Ideal Gas Law PV = nRT, if the volume is halved and the temperature is doubled, the pressure will increase fourfold, because pressure is directly proportional to temperature and inversely proportional to volume.
In the Ideal Gas Law, P is pressure, V is volume, n is the number of moles of gas, R is the gas constant, and T is temperature. A halving of the volume and doubling of the temperature means the pressure will increase by a factor of four.
