Why are some collisions unsuccessful
- particles don’t have enough energy
- particles facing the wrong way
- amount of energy the particles need = activation energy (Ea)
How do you increase rate of reaction
- Increase percentage of collisions which are successful
* Increase frequency of collisions
Larger surface area in reaction =
- Faster rate of reaction
- Increase number of particles that can react in certain volume
- Increase frequency of collision, Increase rate
What is an ion
Ions are electrically charged particles formed when an atom lose or gain electrons
Effect on temperate on reaction
- As temperature increases so does the rate
* Particles have more energy
What is a catalyst
•Speed up rate of reaction without being used up in reaction
Define Covalent Bonds
Electrostatic force of attraction between positive nuclei and shared pair of electrons
Define Ionic bonds -
- Very strong
- Need a lot of energy to break
- Ionic compounds have high melting and boiling point
Define Intermolecular Forces -
- The strength of I.M.F depends on the size of the molecule.
* Bigger molecule = stronger I.M.F
What is a Diamond?
- Giant covalent structure
- Each carbon is covalently bonded to 4 other C
- High melting point
- Hard
- Insoluble
What is a Graphite?
- Giant covalent structure
- Layers of carbon in hexagon
- Each C bonded to 3 other C
- Spare C is delocalised
- Conducts electricity
- Act as lubricant because layers have weak attraction between each so layers can slide over eachother
Why does water have a low boiling point
- Weak attraction due to intermolecular forces
* IMF weak so don’t require lots of energy to break
Colour of chlorine at room temperature
- Green
* Gas
Colour of bromine at room temperature
- Red/ brown
* Liquid
Colour of Iodine at room temperature
- Grey
* Solid
Define a hydrocarbon
•Compound contains only hydrogen and carbon
Test for unsaturation
Bromine water turns from orange to colourless rapidly
Fractional Distillation order : (Really Gay Kids Don’t Fuck Bitches)
Refinery gases (Home heating) Gasoline (Car petrol) Kerosene (Planes) Diesel (Lorry fuel) Fuel oil (Ships) Bitumen (Road tarmac) •In order of lowest to highest boiling point
What temperature does crude oil turn into a gas
500 degrees
What is Crude Oil
Mixture of loads of different compounds, mixture of hydrocarbons
Define an Isomer :
2 molecules with same chemical formula but different structure
Define a homologous series :
•Family is compounds with some chemical properties and trend in physical properties
(e.g. bpt and mpt)
What is cracking :
Turning less useful, long chain alkanes (in crude oil) into short chain, more useful alkanes and alkanes
Define a polymer :
- Long chain molecules made up of lots (poly) of repeating units
- Units are small molecules which have a C=C
