Chemistry Unit 2

Solid

Held in a compact & fixed crystal lattice framework shape with a small amount of space between particles (little kinetic energy)

Liquid

There is decent space between particles & takes the shape of its container so particles move together (higher kinetic energy)

Gas

Tons of space between particles and moves in all directions individually within its container (high kinetic energy)

As we add or remove energy from matter…

we change the kinetic energy of the particles (change of state)

The KMT of gases #1

Individual gas particles have essentially no volume compared to the space between particles

The KMT of gases #2

No attractive forces exist between the particles in a gas

The KMT of gases #3

Gases are very energetic & move randomly in all different directions in a straight line

The KMT of gases #4

When gas particles collide with each other or a container wall, the collision is elastic- That is, there is no loss of kinetic energy

The KMT of gases #5

The average kinetic energy of a gas is directly related to its temperature, therefore, the higher a temperature, the higher the kinetic energy

The Kinetic Molecular Theory of gases applies to

Ideal gases

Standard Temperature and Pressure (STP)

T = 273K, P=100kPa

Standard Atmospheric Temperature and Pressure (SATP)

T = 298K, P=100kPa

Pressure

The force and frequency of container wall collisions

Volume

Space available in container for molecular movement

Temperature

Average kinetic energy of molecules, always in units of Kelvin

Pressure unit conversions

101.3 kpa = 760.0 mmHg = 760.0 Torr = 1.00 atm

Volume unit conversions

1.00L = 1000.0mL = 1000.0 cm cubed

Boyles Law

If the pressure on a gas is increased, the volume will decrease and if the pressure on a gas is decreased the volume will then increase

Charles Law

If the temperature of a gas is increased, the volume will increase and if the temperature of a gas is decreased, volume will decrease

Gay-Lussac’s Law

If the temperature of a gas in increased, pressure will increase and if temperature is decreased the pressure will decrease

Dalton’s Law of Multiple Proportions

The masses of elements that combine in a reaction can be expressed in whole number ratios

The Law of combining volumes

When gases react at the same temperature and pressure, the volume of the reactant & product gases can be expressed in whole number ratios

Dalton’s Law of Partial Pressures

The total pressure of a mixture of unreactive gases is equal to the sum of the partial pressures of each gas

Vapour pressure of water

The pressure exerted by water vapour leaving the liquid water

Ideal gas

has negligible volume & negligible attractive forces between molecules following KMT exactly

Ideal gas law units

P= kpa, T= Kelvin, V= L, n= mol, R= 8.314 kpaL/Kmol

Avogrado’s Law

If ideal gases contain the same number of molecules (or moles) at the same temperature and pressure then they will take up the same amount of volume

Molar volume (L/mol)

The volume occupied by 1.00mol of gas at a give temperature and pressure