Unit 17: Gases

We have learned about electronic structures of atoms and about how atoms combine to form molecules and ionic substances. In everyday life, however, we don’t have direct experiences with atoms. Instead, we encounter matter as collection of enormous numbers of atoms or molecules that make up gases, liquids, and solids. In the atmosphere, it’s the action of such large collections of atoms and molecules that are responsible for our weather—the gentle breezes and the gales, the humidity and the rain. Tornadoes form when moist, warm air at lower elevations converges with cooler, dry air above it. The resultant air flows produce winds that can approach speeds up to 500 km/hr.

It was his interest in weather that motivated John Dalton to study gases and eventually led him to propose the atomic theory of matter. We now know that the properties of gases, liquids, and solids are readily understood in terms of the behavior of their component atoms, ions, and molecules.

In this unit, you will:

1. State Boyle’s Law, Charles’s Law, and Gay-Lussac’s Law.

2. Apply the three gas laws to problems involving pressure, temperature, and volume of a gas.

3. State the relationship among temperature, volume, and pressure as the combined gas law.

4. Apply the combined gas law to problems.

5. Relate the amount of gas present to its pressure, temperature, and volume by using the Ideal Gas Law.

6. Apply the Ideal Gas Law to various problems.

7. Determine the volume ratios for gaseous reactants and products by using coefficients from a chemical reaction.

8. Calculate the amount of gaseous reactants and products in a chemical reaction using the various gas laws.

ª Notes

· Power Point

ª Homework