Organic Chemistry Flashcards
What is crude oil?
A finite resource made of the remains of ancient biomass (mostly plankton) that was buried in mud
What is the formula for alkanes
CnH2n+2
What are the first 4 alkanes ?
Methane, ethane, propane, butane
How does fractional distillation work ?
- the crude oil is heated in the fractioning column and the oil evaporates and condenses at a number of different temperatures
- the many hydrocarbons in crude oil can be separated into fractions each of which contains molecules with a similar number of carbon atoms
- the vaporized oil rises up the column and various fractions are tapped off at the different levels where they condense
What are the different fractions of crude oil, short to long molecule ?
Gases, petroleum gas, Naphtha, kerosene, diesel oil, heavy fuel oil, bitumen
Used for gases from crude oil ?
Domestic heating and cooking
Uses for petrol from crude oil ?
Car fuel
Uses for Naphtha from crude oil ?
Chemicals
Uses for kerosene from crude oil ?
Fuel for aircraft
Uses for diesel from crude oil ?
Fuel for some cars and trains
Used for heavy fuel oil from crude oil ?
Fuel for heavy ships and power stations
Uses for bitumen for roads and roofs from crude oil ?
Roofs and roads
Give some properties of long hydrocarbons ?
- high boiling point
- more viscous
- less volatile (don’t evaporate easily)
- less flammable
Give some properties of short hydrocarbons ?
- lower boiling points
- less viscous
- more volatile (evaporate easily)
- more flammable
Word Equation for the combustion of hydrocarbons?
Hydrocarbon + oxygen ~> carbon dioxide + water
What process turns hydrocarbons into smaller more useful molecules ?
Cracking
What are the 2 processes of cracking ?
- passing them over a hot catalyst (catalytic cracking)
- mixing them with steam and heated to a high temperature so thermal decomposition occurs (steam cracking)
Saturation of alkanes vs alkanes ?
Alkanes = saturated
Alkanes = unsaturated
General formula of alkenes ?
CnH2n
What bond does an alkene have to have ?
A double carbon=carbon bond
What are the first 4 alkenes ?
Ethene, propene, butene, pentene
What colour does bromine water turn when. Reacted with alkenes ?
Orange ~> colourless
Because the double bond makes it more reactive (unsaturated)
Reaction of alkene and oxygen ?
Tend to burn in the air with smoky flames because of incomplete combustion (meaning carbon or carbon monoxide is formed)
What functional group is in alcohols
OH
What are the first four alcohols ?
Methanol, ethanol, propanol, butanol
Reactions of methanol, ethanol, propanol and butanol ?
- burn in air to get ridiculous carbon dioxide and water
- they dissolve in water to form a neutral solution (ph 7)
- react with sodium to produce a hydrogen and a salt
- react with oxidizing agents to form carboxylic acid
Reactions of methanol, ethanol, propanol and butanol ?
- burn in air to get ridiculous carbon dioxide and water
- they dissolve in water to form a neutral solution (ph 7)
- react with sodium to produce a hydrogen and a salt
- react with oxidizing agents to form carboxylic acid
Uses of methanol ?
Chemical feedstock, anti-freeze, biodiesel, fuel
Uses of ethanol ?
Alcoholic drinks, solvent, fuel
How can ethanol be produced ?
- fermentation of sugar with yeast using renewable sources
- conditions of about 35°C, anaerobic, and yeast enzyme catalyst
- sugar ~> ethanol + carbon dioxide
What functional group do carboxylic acids have ?
-COOH
What are the first four carboxylic acids ?
Methanoic acid, ethanoic acid, propanoic acid, butanoic acid
Reactions of carboxylic acids ?
- dissolve in water to produce acidic solutions
- react with metal carbonates to produce carbon dioxide, a salt and water
- react with alcohols in the presence of an acid catalyst to produce esters
Example of an ester ?
Ethyl ethanoate
Is carboxylic acids weak or strong acids and why ?
Weak acid, do not completely ionize in solution so have a higher pH (less acidic)
Give 2 examples of polymers ?
Poly(ethene), poly(propane)
What reaction is used to make alkenes into polymers ?
Additional polymerisation, joining small moonomers into larger polymer molecules
What is condensation polymerisation ?
When monomers with 2 functional groups react and join together, usually losing small molecules such as water
What do amino acids react to make by condensation polymerisation ?
- (2 functional groups of amine, carboxylic)
- react to produce polypeptides
- different amino acids can be combined in the same chain to produce protein
Name some naturally occurring polymers ?
DNA
Protein (monomer = amino acid)
Starch (monomer = glucose)
Cellulose (monomer = glucose)
Structure of most DNA molecules ?
- 2 polymer chains
- made from 4 different monomers called nucleotides in the form of a double helix
