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Flashcards in Topic 7 Deck (30):
1

What is a hydrocarbon?

A hydrocarbon is any compound that is formed from carbon and hydrogen atoms only.

2

What are Alkanes?

Alkanes are the simplest type of hydrocarbon which has the general formula CnH2n+2.
All alkanes have a C-C single bond.

3

What is the homologous series?

A group of organic compounds that react in a similar way.

4

What are saturated compounds?

Where each atom forms four single covalent bonds.

5

What are the first four alkanes?

Methane CH4
Ethane C2H6
Propane C3H8
Butane C4H10

6

How do short chained hydrocarbon effects it’s properties?

More runny
More volatile
More flammable
Lower boiling point

7

What is the complete combustion of a hydrocarbon?

Hydrocarbon + oxygen -> carbon dioxide + water (+ energy)

8

What is the process of fractional distillation?

1) Oil heated until most of it is becomes gas which enters the fractionating column.
2) Column heated gradually from the bottom.
3) Longer hydrocarbons condense back into a liquid and drain out the column, while shorter hydrocarbons condense near the top of the column and is drained out.
4) The crude oil solutions are separated out into different fractions.

9

What is cracking and what does cracking produce?

Cracking is a thermal decomposition reaction - breaking molecules down by heating them.
Cracking produces alkenes.

10

What is the process for catalytic cracking?

1) Heat long chained hydrocarbons to vaporise them(turn them into a gas).
2) The vapour is passed over a hot powdered aluminium oxide catalyst.
3) The long-chain molecules split apart on the surface of the specks of catalysts - this catalytic cracking.

11

What is the process of steam cracking?

Vaporise long chained hydrocarbon, mix them with steam and then heat them to a very high temperature.

12

What are Alkenes?

Alkenes are hydrocarbons which have a double bond between two of the carbon atoms in their chain.
Double bond C=C, making Alkenes unsaturated.
General formula for Alkenes CnH2n

13

What are the first four Alkenes?

Ethane C2H4
Propene C3H6
Butane C4H8
Pantene C5H10

14

What is incomplete combustion?

When there is not enough oxygen incomplete combustion occurs: Alkene + oxygen -> carbon + carbon monoxide + carbon dioxide + water (+ energy)

15

What is a functional group?

A group of atoms in a molecule that determine how that molecule typically reacts.

16

What is addition reactions?

Where the carbon double bond will open up to leave a single bond and a new atom is added to each carbon.

17

What is known as the addition of hydrogen and how does it react with an alkene?

Hydrogenation
Hydrogen can react with the double bonded carbons to open up the double bond and from the equivalent, saturated, alkane.

18

What forms when reacting steam with alkenes and the process?

Alcohols are produced.

Alkenes react with steam, water is added across the double bond and an alcohol is formed.

After the reaction has taken place the reaction mixture is passed from the reactor into the condenser. Ethanol and water have a higher boiling point than ethane so unreacted ethene gas is recycled back through. Alcohol can be purified with fractional distillation.

19

What forms when reacting halogens with alkenes?

Alkenes will react with halogens such as bromine, chlorine, iodine. The molecules formed are saturated with C=C bonded to a halogen atom.


20

What is the process to test for alkenes with bromine?

1) When orange bromine water is added to a saturated compound, like an alkane, no reaction will happen and it’ll stay bright orange.
2) If it’s added to an alkene the bromine will add across the double bond, making a colourless dibromo-compound — so the bromine water is decolourised.

21

What is a Polymer?

Polymers are long molecules formed when lots of small molecules called monomers join together. The reaction is called polymerisation— and it usually needs a high temperature and a catalyst.

22

What is addition polymerisation?

Where lots of unsaturated monomer molecules (alkenes) can open up their double bonds and join together to form polymer chains.

23

What is the general formula of an alcohol?

CnH2n+1OH

24

What are the first four alcohols?

Methanol, ethanol, propanol, butanol.

25

What is the equation for fermentation of ethanol?

Sugar (Yeast)-> ethanol + carbon dioxide

26

What is the ideal temperature for an enzyme?

37*C

27

What is the homologous series for carboxylic acids?

COOH

28

What are the first 4 carboxylic acid?

Methanoic acid, ethanoic acid, propanoic acid, butanoic acid.

29

How are Esters formed and what is it’s functional group?

An Ester are formed from an alcohol and a carboxylic.

COO

30

What is a condensation polymerisation?

A reaction which involves monomers with different functional groups.