Organic chemistry

Created by

Amelie Viney

Cards (29)

What is crude oil?
A mixture of compounds, a fossil fuel consisting of the remains of ancient biomass
What is a hydrocarbon? 
A compound made up exclusively of hydrogen and carbon atoms
What are alkanes? 
Saturated hydrocarbons of general formula CnH2n+2
What is a homologous series?
Series of compounds with the same general formula, same functional groups and similar chemical properties
Describe the combustion of hydrocarbons!
Exothermic reaction occurring when hydrocarbons are reacted with oxygen
-> Complete combustion produces carbon dioxide and water
-> Incomplete combustion produces carbon or carbon monoxide and water
Describe the physical properties of alkanes:
> First few in series are gases, then change to liquids, then to solids
> In general, boiling points and viscosity increase as molecules get bigger
> Volatility and flammability decrease as molecules get bigger
> Poor reactivity
Explain how fractional distillation to crude oil takes place:
Crude oil is heated and vapourised
Vapour rises up the fractionating column
-> The column is hotter at the bottom and cooler at the top
Hydrocarbons cool as they go up the column as condense at different heights as they have different boiling points
Large molecules, high boiling points: collected at bottom
Small molecules, low boiling points: collected at top
-> This gives fractions, which can be used in various ways
What is cracking? 
When large hydrocarbons are thermally broken down into smaller and useful molecules
What type of reaction is cracking?
Thermal decomposition
What are the conditions for cracking?
Catalytic cracking: Reactant heated to vapour, passes over a hot catalyst
Steam cracking: heated to vapour mixed with steam and heated to high temperatures
How are the products of cracking used?
The products are alkanes and alkenes
Used as polymers and starting materials for synthesis
What is an alkene?
Unsaturated carbon
Contains a C=C bond
General formula CnH2n
What is the test for alkenes?
Add bromine water
colour change occurs from orange to colourless
Describe the combustion of alkenes:
They burn with smoky flames due to incomplete combustion
Describe addition reactions of alkenes:
Addition atoms across the carbon-carbon double bond so that the double bond becomes a sing carbon-carbon bond
> With hydrogen- hydrogenation: requires a higher temp and a nickel catalyst
> With steam- hydration: requires high temp, pressure and concentrated phosphoric acid as a catalyst
> With Br2/Cl2/I2- addition of halogens
What is an alcohol? 
An organic compound that contains an -OH functional group
State characteristics of methanol, ethanol, propanol, and butanol:
> Dissolve in water to form a neutral solution
> React with sodium to form hydrogen
> Burn in oxygen
> React carboxylic acids in presence of acid catalyst to form esters
What does oxidation of the alcohols lead to?
Carboxylic acid
State the conditions requires for fermentation of glucose:
30 degrees C
Aqueous solution of the glucose
Absence of air
Yeast added
What are carboxylic acids? 
Organic compounds that contain a COOH functional group
State characteristics of carboxylic acids:
> Dissolve in water to form an acidic solution (contain H+ ions)
> React with metal carbonates to form carbon dioxide
> React with alcohols to produces esters
> React with metals to give off hydrogen gas
What type of acid is carboxylic acid?
A weak acid
-> They are partially dissociated in water, thus the pH of a carboxylic acid in solution is not as low as a solution of a strong acid of the same concentration
What is an ester and how is it formed?
An organic compound containing a -COO- functional group, formed from carboxylic acid and alcohol in the presence of a sulfuric acid catalyst
They have a fruity smell
What is a polymer? How do polymers cot sing C=C bond form polymers? 
> A polymer is a long chain molecule which is made by lots of smaller molecules joining together
> C=C bonds open up and many smaller molecules (monomers) join together to form a chain (a polymer)
> It is called an addition polymerisation reaction
What is a condensation polymer?
A polymer, made in condensation polymerisation
-> many molecules join together, the polymer is formed but also a small molecule is released, e.g H2O, HCl
> Polyesters, e.g terylene
> Polyamides, e.g nylon
What is an amide bond?
Similar to the ester bond with O replaced by N
Like an ester, it contains the C=O group
What is an amino acid?
An organic compound that contains both an carboxylic acid functionality (COOH) and an amine functional group (-NH2)
How do amino acids make proteins? What are polypeptides?
By numerous condensation polymerisation reactions
Proteins are polymers made of amino acids (monomers)
Polypeptides are also made by condensations polymerisation at ion of amino acids but are shorter than proteins
What is DNA? 
> A material that makes up chromosomes
> DNA is made of two polymer chains that are held together in a double helix
> Each polymer chain can be made from 4 different monomers- nucleotides