4- Organic Chemistry❗️ Flashcards
What is the general formula for alkanes?
CnH2n+2
List the first five alkanes
Methane Ethane propane butane pentane
Why are alkanes saturated?
There are only single bonds between the carbon atoms
Why are alkenes unsaturated molecules?
They contain a double bond between two of the carbon atoms in a chain
What is the general formula for alkenes?
CnH2n
List the first alkenes
Ethene
propene
Butene
How do you test for alkanes and alkenes?
Using bromine water to test saturation
What colour does bromine go when added to saturated alkanes?
Stays orange
What colour does bromine go when added to unsaturated alkenes?
Turns colourless
What is the general formula of an alcohol
CnH2n+1OH
What is the functional group of alcohols?
-OH
Name the first 4 alcohols?
Methanol
ethanol
propanol
butanol
What do alcohols form when oxidised?
Carboxylic acids
What is the word equation for complete combustion?
Hydrocarbon + oxygen —> carbon dioxide + water
When does complete combustion happen?
When there is plenty of oxygen
What does incomplete combustion produce?
Carbon Dioxide
water
carbon monoxide
When does incomplete combustion happen?
When there is not enough oxygen
How does acid rain form?
sulphur dioxide + nitrogen oxides mix with water vapour in clouds they form dilute sulphuric + nitric acid
What’s the equation for production of ethanol through steam?
phosphoric acid
Ethanol + steam —————————> ethanol
What is fermentation?
When sugar is converted into ethanol using yeast
Give the equation for fermentation
Glucose—> ethanol + carbon dioxide
Top of column
Short chain
What do homologous series have in common?
- same general formula
- same functional group
- similar chemical properties
What are isomers ?
compounds with the same molecular formula but different displayed formula
What is bitumen used for ?
Surfacing roads + roofs
What is kerosene used for?
Jet fuel
What is fuel oil used for?
Ships + power stations
What is liquified petroleum gas used for?
Domestic heating + cooking
Describe properties of short chain molecules
- less viscous
- more flammable
- lower boiling points
- more volatile
Describe properties of long chain molecules
- more viscous
- less flammable
- higher boiling points
- less volatile
What is the definition of cracking?
The thermal decomposition of long chain hydrocarbons into shorter more useful ones
Hydrocarbon + oxygen —>
Carbon dioxide + water
What kind of reactions do all alkenes undergo?
Addition reactions
What can alkanes react with?
Bromine (need UV light) - substitution reaction
