TOPIC 1
Particulate Nature of Matter
The Mole Concept
Reacting Masses and Volumes
Gas Laws
All matter is made up of very small particles in constant random motion
Can't be seen with a microscope
There are spaces between these particles, which are different for solids, liquids and gases.
These three states differ in:
- Arrangement of particles
- Movements of particles
- Forces of attraction between particles
- Energy of particles
Solid
Gas
Liquid
Closely packed in an orderly arrangement
- Vibrates and rotates about fixed positions
- Very strong forces of attraction between particles
- Low average kinetic energy
- Close packed and in disorderly arrangement
- Slide and roll over each other
- Some forces of attraction exist between particles
- Moderate average kinetic energy
- Far apart and in random arrangement
- Move very fast and freely to occupy all available space
- Negligible forces of attraction between particles
- High average kinetic energy
Boyle's Law
Charles' Law
Avogadros' Law
Ideal Gas Law
Combined Gas Law
The pressure of a fixed mass of gas at constant temperature is inversely proportional to the volume
PV=k1
The volume of a fixed mass of gas at constant pressure is directly proportional to the absolute temperature
V/T=k2
At a fixed temperature and pressure, the volume of gas is directly proportional to the mole of gas
P/T=k3
States the relationship between the first 3 laws
PV/T=k4
With known values of pressure, volume, temperature and mass of the gas, the last unknown, the molar mass of the gas can be determined.
PV=nRT
n = mass of gas (m) / molar mass of gas (Mr)
Stoichiometry is a general term used to describe any quantitative relationship within a chemical reaction
Percentage yield = actual yield/theoretical yield x 100
Percentage purity = mass of pure substance/total mass of substance x 100
Molar volume
22.7dm3 mol-1 at STP (273K and 100kPa)
24.0dm3 mol-1 at RTP (298K and 100kPa)
Avogadro’s Law states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules
The amount of substance that contains as many elementary particles as there are atoms in 12g of carbon-12
N = nL
N = the number of particles
n = the amount (number of mol)
L = Avogadro’s constant
Can be used to determine empirical formula of compounds
Can be used to find mass, concentration, volume and molarity of substances
Number of moles = Molarity x Volume in dm3
Mass (g) = Number of moles x Mr
Volume of gas (dm3) = Number of moles x Molar volume
Number of particles = Number of moles x Avogadro's number
Number of moles = Volume (idm3) x Concentration (mol/dm3)