The Gaseous State

The Gaseous State

Learning Objectives

• Describe the postulates of Kinetic Molecular Theory

• Describe the Empirical Gas Laws

• Identify the factors that affect the pressure of a gas

• Identify and describe the relationship between pressure, temperature, volume and the amount of substance

Kinetic Molecular Theory

1. Gases consist of tiny particles (atoms or molecules)

Kinetic Molecular Theory

2. These particles are so small, compared with the distances between them, that the volume (size) of the individual particles can be assumed to be negligible (zero).

Kinetic Molecular Theory

3. The particles are in constant random motion, colliding with the walls of the container. These collisions with the walls cause the pressure exerted by the gas.

Kinetic Molecular Theory

4. The particles are assumed not to attract or to repel each other.

Kinetic Molecular Theory

5. The average kinetic energy of the gas particles is directly proportional to the Kelvin temperature of the gas.

Multiple Select

Using the postulates of the kinetic molecular theory, explain why a gas uniformly fills a container of any shape.

• Gases are composed of molecules that are in continuous motion, travelling in straight lines and changing direction only when they collide with other molecules or with the walls of a container

• The molecules composing the gas are negligibly small compared to the distances between them.

• The pressure exerted by a gas in a container results from collisions between the gas molecules and the container walls.

• The average kinetic energy of the particles in a sample of gas is proportional to the absolute temperature.

Multiple Choice

Which of the following is not true about the volume of a gas?

• Most of the volume is empty space.

• The volume is about 10 times greater than that occupied by an equal number of particles in the liquid or solid state.

• The volume is occupied by particles in continuous, rapid, random motion.

• Generally, the volume can be easily changed

Multiple Choice

The more energy that particles have, the ___ they move.

• slower

• faster

Multiple Choice

The pressure exerted by a gas does not depend on __.

• temperature

• volume

• number of moles present

• the identity of the gas

Multiple Choice

• Flask 1 contain the most molecules

• Flask 2 contain the most molecules

• Flask 3 contain the most molecules

• Flask 4 contain the most molecules

Boyle's Law

Pressure and Volume have an inversely proportional relationship

PV = PV

Multiple Choice

Which two variables must be held constant for Boyle’s Law to apply?

• pressure & volume

• volume & temperature

• temperature & moles (amount of gas)

• volume & moles (amount of gas)

Multiple Choice

The relationship of which two variables are compared in Boyle's Law?

• pressure & volume

• volume & temperature

• temperature & moles (amount of gas)

• volume & moles (amount of gas)

Multiple Select

Choose ALL that Boyle's Law explains

• breathing

• popping the top off a water bottle after twisting the bottom

• air pump

• blowing up a balloon

Charles' Law

Volume and Temperature have a DIRECT relationship

Temperature MUST be in KELVIN

Celsius to Kelvin - add 273.15

V/T = V/T

Multiple Select

The relationship of which two variables are compared in Charles' Law?

• pressure

• volume

• temperature in Kelvin

• moles

Multiple Select

Choose ALL that Charles' Law explains

• breathing

• popping the top off a water bottle after twisting the bottom

• the volume in your tires decreasing on a freezing cold day

• the lid popping off a container that has been heated in the microwave

Avogadro's Law

Volume and Moles have a DIRECT relationship

v/n = v/n

Multiple Select

Click on the examples of Avogadro's Law

• putting air into a flat tire

• a tire going flat

• the egg in the flask

• putting a dented ping pong ball in boiling water

Multiple Choice

Which container will have a lower pressure?

• left

• right

• they both have the same pressure

• I don't know

Multiple Choice

When Volume increases then Pressure must...

• Increase

• Decrease

Multiple Choice

When Pressure increases then the Volume must...

• Increase

• Decrease

Multiple Choice

A gas at a volume of 4 liters is at a pressure of 2 atm. The volume is changed to 16 Liters, what must the new pressure be?

• 2 atm

• 12 atm

• 10 atm

• 0.5 atm

Multiple Choice

If a hairspray can is heated, what can be expected of the pressure of the gas inside the can?

• The pressure will increase

• The pressure will decrease

• The pressure will remain constant

• The pressure will equalize

Multiple Choice

A student inflates a balloon with helium then places it in the freezer. The student should expect

• the balloon's volume to increase

• the balloon's volume to decrease

• the balloon's moles to increase

• the balloon's moles to decrease

Multiple Choice

If the temperature of a gas is doubled from 100K to 200K, what happens to the volume of the gas?

• Cuts in half

• Doubles

• Triples

• Stays the Same

Multiple Choice

According to Charles Law, if Temperature of a gas increases Volume will....

• Increase

• Decrease

• Stay the Same

Multiple Choice

According to Charles Law, the relationship between Temperature and Volume can best be described as....

• Direct Relationship

• Inverse Relationship

Multiple Choice

If the Kelvin temperature of a gas is doubled, the volume of the gas will increase by ____.

• A factor of 2

• A factor of 1

• A factor of 3

• A factor of 0.5

Poll

This lesson is so easy to understand!!!

• I strongly agree.

• I agree.

• I neither agree nor disagree.

• I disagree.

• I strongly disagree.