Chemistry - Gases

Mr. Becker

definition of a barometer

an instrument that measures the amount of atmospheric pressure

partial pressure meaning

the pressure of a single gas in a container

5 postulates of the Kinetic Theory of Gases

1. Gases are in constant random motion

2. Since gases are so small, the volume is assumed to be negligible

3. There’s no attraction or repulsion between gas particles

4. The average kinetic energy is proportional to the Kelvin temperature

5. Any collision of two gases is elastic

What does it mean for a gas to act like a “real gas”?

• have actual volume

• actually attract other gas particles in low temperature or high pressure

What allows us to treat all gases as the same?

• usually, gases act as if they aren’t attracted to eachother

• Avagadro’s Law : if the particles are at the same temp and pressure, then they have the same number of molecules regardless of type

• all gases behave similarly at the same temp.

How does a barometer measure atmospheric pressure

by balancing it against a liquid which pushes against the mercury a certain amount depending on the pressure of the atmosphere

What to do when you must determine the liters of a substance needed to react completely in grams with another substance?

convert grams to moles of the second substance

use the moles in ideal gas law to get the volume

What should you do to solve a problem that has you finding the mass of a substance to completely react with L of another substance?

Ideal gas law to get the moles

use the moles to convert to grams of the first substance