Properties of gases

Gas (definition)

A substance that has no well-defined boundaries and diffuses rapidly to fill any container in which it is placed

How to convert degrees celsius to kelvin?

+273

What is the standard temperature?

0 degrees celsius

Unit of pressure

Pa (Pascals)

How many pascals is 1kPA?

1000 Pascals

How many pascals are in 1 hPA?

100 Pa

What is the standard pressure?

100 kPa

1 m³ = ?L

1000L

How to convert cm cubed to m cubed

x 1,000,000

What does s.t.p stand for?

Standard Temperature and pressure

What are the conditions of s.t.p.?

100,000 Pa and 273K in temperature

Boyle’s Law (definition)

At constant temperature, the volume of a fixed mass of a gas is inversely proportional to its pressure

Charles’ Law (definition)

At constant pressure, the volume of a fixed mass of gas is directly proportional to its Kelvin temperature

Equation of combined gas law

P1V1/T1 = P2V2/T2

What is P1?

Initial pressure

What is P2?

Final pressure

What is V1?

Initial volume

What is T1?

Initial temperature

What is P2?

Final pressure

What is V2?

Final volume

What is T2?

Final temperature

Ideal gas law (definition)

pV = nRT

What is p in the ideal gas law?

Pressure

What is V in the ideal gas law?

Volume

What is V measured in in the ideal gas law?

m cubed

What is n in the ideal gas law?

Moles

What is R in the ideal gas law?

Universal gas constant

What is T in the ideal gas law?

Temperature

What is T measured in in the ideal gas law?

Kelvin

Gay-Lussac’s Law of Combining Volumes (Definition)

In a reaction between gases at the same temperature and pressure, the volumes of the reacting gases, and gaseous products, are in simple whole number ratios

Avogadro’s Law (definition)

Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules

How much volume does 1 mole of gas at s.t.p. occupy?

22.4L

How much volume does 1 mole of gas at room temperature and pressure occupy?

24L

Ideal gas (definition)

One that obeys all of the assumptions of the kinetic theory of gases under all conditions of temperature and pressure

First 3 Assumptions of the kinetic theory of gases

Gases made up of particles which are randomly colliding with other particles and the walls of the container. There are no attractive or repulsive forces between the gas molecules. Volume of gas molecules are negligible compared to volume of their container

Last 2 Assumptions of the kinetic theory of gases

Collisions between the molecules are perfectly elastic. Average kinetic energy of molecules is proportional to Kelvin temperature of gas

Limitation to the kinetic theory of gases (2)

Attractive forces do exist between gas molecules due to Van-der-Waals forces dipole dipole forces and hydrogen bonding. The volume of the gas molecules is not negligible compared to the distances between them

Under what conditions are gases closest to ideal behaviour?

Low pressure and high temperature

The weaker the intramolecular force the …

Closer to ideal gas

Molecules with smaller volume are …

Closer to ideal gas

Volatile liquid (definition)

A liquid that is easily vapourised and has a low boiling point.