Organic Chemistry Flashcards
Define homologous series
A family of organic compounds where they have a same general formula, similar chemical properties, gradual change in physical properties and Differ by CH2 down the group
Which 2 elements make up a hydrocarbon
Hydrogen and carbon
What is the general formula of Alkanes
C(n)H(2n+2)
What does the prefix meth mean
1
What does the prefix eth mean
2 carbons
What does the prefix prop mean
3 carbons
What dies the prefix but mean
4 carbons
Define fossil fuels
Fossil fuels are formed over millions of years from dead plants and animals. Eg crude oil, peat and natural gas
What is fractional distillation
Continual process of evaporation and condensation.
How does a fractionating column work?
When hydrocarbons enter the column they are vaporised. As they rise up through the column different compounds condense at their different boiling points.
What are the 3 stages of the petro-chemical industry
- Extracting crude oil from its source
- Transported to refineries, fractional distillation separates it into different hydrocarbons
- Hydrocarbons obtained by fractional distillation are used not only as fuels but used in the manufacture of dyes, plastics, fertilisers, medicines, paints and lubricants
What are environmental concerns of the petrochemical industry
Transports of crude oil can result in spills and leakages
Drilling for oil in the sea bed can result in leaks
Air pollution by burning fossil fuels as carbon dioxide is released
Define cracking
Cracking is the breakdown of larger/longer (less useful) saturated hydrocarbon molecules (alkanes) into smaller/shorter more useful ones, some of which are unsaturated (alkenes).
Define combustion
The reaction in which a fuel reacts with oxygen producing oxides and releasing heat
What is complete combustion
Burning in an excess of air (more than enough), when all the carbon turns into carbon dioxide
What is incomplete combustion
Gives carbon monoxide and water
What is the word equation for complete combustion
Hydrocarbon + oxygen —> Carbon dioxide + water + (energy)
What is the equation for incomplete combustion
Hydrogen + oxygen —> carbon monoxide + water + (energy)
What is the use for refinery gases
Bottled gasses
What is the use for petrol
Fuel for cars
What is the uses of Naptha
Chemicals and plastics
What is the use of kerosene
Fuel for aircraft
What is the use of diesel
Fuel for cars and trains
What is the use of fuel oil
Fuel for ships
What are uses of bitumen
Surfacing roads as raid tar and sealing roofs
In extreme circumstances with an inadequate supply of oxygen for combustion what can be produced
Soot
Hydrocarbon + water —> carbon + water
What is the test for carbon dioxide
Bubble through limewater, will turn milky
How is carbon monoxide a toxic gas
It combines with haemoglobin in the blood reducing its capacity to carry oxygen. It is colourless and odourless
What is the general formula for alkenes
C(n)H(2n)
What is an alkene and what makes it different to an alkane
Alkenes are another example of a homologous series, they are also hydrocarbons. They are said to be unsaturated as they have one carbon-carbon double bond
What are the first 4 alkenes
Ethene
Propene
But-1-ene
But-2-ene
Define alkene
An unsaturated compound which contains at least one c=c double bond
Define functional group
Reactive group in a molecule
What colour flame does alkenes burn in
Orange
What colour flame does an alkane burn in
Blue
Why can alkenes easily go under addition reactions
The double bond breaks and atoms add onto the two carbon atoms across the double bond. The product then contains a c-c single bond and is saturated
How to distinguish between an alkane and an alkene
Shaking hydrocarbon with bromine water. An addition fraction takes place where bromine molecule adds across the double bond of alkene to produce a halogenalkane.
Colour change can be seen in alkene as it goes from orange to colourless.
Word equation of addition reaction of ethene with hydrogen
Ethene + hydrogen —> ethane
Nickel catalyst also used
Word equation of Ethene with steam (addition reaction)
Ethene + steam —> ethanol
Phosphoric acid catalyst used and done at high temp
