Organics I Flashcards
What is a hydrocarbon? + What is a crude oil?
Hydrocarbon- molecule/carbon made up of carbon and hydrogen ONLY
Crude oil- Mixture of hydrocarbons
Describe the process of fractional distillation
- Crude oil is heated until most of it is vapour and passed into the bottom of the fractionating column
- The fractionating column is cooler at the top and hotter at the bottom
- Once a hydrocarbon reaches its boiling point, it condenses and is piped off as a liquid
- The lower the boiling point the further up the column it reaches
- Small fractions have low boiling points and are collected at the top
Describe the order of hydrocarbons going up the fractionating column
Refinery gasses, petrol, kerosine, diesel, fuel oil, bitumen
Describe the properties of hydrocarbons at the top of the column
Small molecules
Low boiling points
Volatile
Flammable
Not viscous
Light in colour
(Opposite at the bottom)
What is cracking and why do we do it?
Splitting long chain hydrocarbons into smaller more useful ones.
There is a high supply of long chain hydrocarbons but low supply (shorter chain hydrocarbons make better fuels and plastics)
What conditions are used for catalytic cracking?
600°C - 700°C
Silica/ alumina catalyst
What is fuel? + what are the products of complete and incomplete combustion?
Fuel- Burns to release energy
Complete- CO2 + water
Incomplete- CO/ C + water
Where are CO2, CO, NO and SO2 found, and why are they bad?
CO2- complete combustion. Climate change
CO- incomplete combustion, binds to haemoglobin to the blood can’t carry as much oxygen
NO- High temps is car engines. Acid rain
SO2- Sulfur impurities found in fuels. Acid rain
