(Done) Organic chemistry (Paper 2) Flashcards
1
Q
Define Hydrocarbon
A
- Any compound that is formed from carbon and hydrogen only
2
Q
What are alkanes
A
- The simplest type of hydrocarbon you can get
3
Q
Features of the alkane series
A
- Homologous series
- Saturated compound
4
Q
Define Homologous series
A
- A group of organic compounds that act in a similar way
5
Q
Define saturated compound
A
- A compound where each carbon atom forms four single covalent bonds
6
Q
List the first four alkanes
A
- Methane
- Ethane
- Propane
- Butane
7
Q
Properties of alkanes in relation to the chain length
A
- The greater the length of the chain, the more viscous the substance
- The shorter the length of the chain, the more volatile (easier to state change)
- The shorter the length of the chain, the more flammable
8
Q
What is produced from complete combustion of hydrocarbons
A
- Carbon Dioxide
- Water
- Large amounts of energy
9
Q
How is crude oil formed
A
- Remains of plants and animals, mainly plankton, that died millions of years ago buried in mud
- Over millions of years under high temperature and pressure, the remains turn into crude oil
10
Q
What method is used to separate different compounds in crude oil
A
- Fractional distilation
11
Q
Process of fractional distilation
A
- Oil is heated until most of it becomes gas
- The gases enter a fractionating column and the liquid is drained off
- There is a temperature gradient in the column
- Different compounds rise as gases and condense and flow out depending on their boiling point
- The crude oil has been split into fractions off roughly similar chain lengths
12
Q
Define cracking
A
- The process of splitting up long-chain hydrocarbons
13
Q
What types of hydrocarbons are produced from cracking
A
- Alkanes
- Akenes
14
Q
What type of reaction is cracking
A
- Thermal decomposition
15
Q
Define thermal decomposition
A
- The process of breaking down molecules by heating them
16
Q
List the steps within catalytic cracking
A
- Heat the long-chain hydrocarbons to vaporise them
- Pass the vapor over a hot powdered aluminium oxide catalyst
- The long-chain molecules split apart on the surface of the catalyst
17
Q
List the steps of steam cracking
A
- Heat the hydrocarbons to vaporise them
- Mix the vaporised hydrocarbons with steam and heat them to a very high temperature
18
Q
Features of Alkenes
A
- Carbon = Carbon double bond which causes them to have two fewer hydrogens compared to alkanes
- Far more reactive than alkanes
19
Q
What happens during combustion of alkenes
A
- Require a large amount of oxygen to combust completely so usually undergo incomplete combustion
20
Q
- What is produced from incomplete combustion of alkenes
A
- A smoky yellow flame
- less energy
21
Q
Define functional groups
A
- A group of atoms in a molecule that determine how a molecule typically reacts
22
Q
What is the functional group of alkenes
A
- C=C (CC)
23
Q
Define hydrogenation
A
- The addition reaction between alkenes and hydrogen
24
Q
What happens in the hydrogenation of alkenes
A
- Hydrogen can react with the double bonded carbons to open up the double bond and form the equivalent, saturated, alkane
- The alkene is reacted with hydrogen in the presence of a catalyst
25
What happens when alkenes react with steam
- Water is added across the double bond and alcohols are produced
- Does not occur without the presence of a catalyst
26
What is the functional group of alchohols
- O - H (OH)
27
How is ethene recycled in the industrial production of ethanol
- After the reaction takes place, the reaction mixture is passed from the reactor into a condenser
- Ethanol and water have a higher boiling than ethene, so both condenser whilst any unreacted ethene gas is recycled back into the reactor
28
What happens when alkenes react with halogens
- The carbons in the C=C double bond become bonded to a halogen each
29
What is a test for alkenes
- When orange bromine water is added to a saturated compound like an alkane, no reaction will happen and it will stay bright orange
- If it is added to an alkene the bromine will add across the double bond, making a colourless dibromo-compound - so the bromine water is decolourised
30
Define Polymers
- Long chain molecules formed when lots of smaller molecules called monomers join together
31
Define Polymerisation
- The reaction of monomers joining together to form polymers
32
What conditions are traditionally required for polymerisation to occur
- High pressure
- Presence of a catalyst
33
What are plastics usually made of
- Often carbon based polymers
- Often alkene monomers
34
Define addition polymerisation
- Unsaturated monomer molecules (alkenes) opening up their double bonds and join together to form polymer chains
35
What are the similar properties of the first four alchohols
- All are flammable and undergo complete combustion in air to produce carbon dioxide and water
- All are soluble in water and the solutions have neutral pH
- All can be oxidised with oxygen to form carboxylic acids
36
What are alcohols used for industrially
- Solvents as they can dissolve most things water can dissolve, but can also dissolve things water cannot dissolve (e.g. hydrocarbons, oils, fats)
- The first four alcohols are used as fuels
37
How is ethanol made via fermentation
- An enzyme in yeast converts sugars into ethanol
- Carbon dioxide is also produced
- The reaction is produced in a solution so the ethanol produced is aqueous
38
What are the optimal conditions for fermentaion
- Around 37 degrees C
- A slightly acidic solution
- Anaerobic conditions
39
Why are the optimal conditions for fermentation optimal
- The optimal conditions provide an environment to maximise activity of the enzyme in yeast, allowing sugars to be converted into alcohol optimally
40
What is the functional group of carboxylic acids
- 0=C-OH (COOH)
41
What is produced when carboxylic acids react with carbonates
- Salt, water and carbon dioxide
42
What is the functional group of esters
- O=C-O (COO)
43
How are esters formed
- When an alcohol and a carboxylic acid react
44
Define condensation polymeriasation
- When monomers react together and bonds form between them, making polymer chains
45
What conditions are required for condensation polymerisation to occur
- Same monomers with different functional groups
- Different monomers with same functional groups
46
What functional groups do amino acids contain
- Amino group (NH2)
- Carboxyl group (COOH)
47
What happens when amino acids undergo condensation polymerisation
- They form polypeptides
48
How do amino acids form chains
- The amino group of an amino acid can bond with the acids group of another
- For every new bond that is formed a molecule of water is lost
49
Define proteins
- One or more long-chains of polypeptides
50
What monomers make up DNA
- Nucleotide monomers
51
What differs between nucleotides
- The small molecule each one contains called a 'base'
- Bases are paired up forming the double helix structure
52
Define sugars
- Small molecules that contain carbon, oxygen and hydrogen
53
What happens when sugars undergo polymerisation
- They form larger carbohydrate polymers e.g. starch and cellulose
