Organic Chem

Question 1

Molecular formula

Answer 1

The actual number of atoms of each element

C2H4

Question 2

Structural formula

Answer 2

Shows the arrangement of atoms carbon by carbon

CH2CH2

Question 3

Empirical formula

Answer 3

The simplest whole number ratio of atoms

CH2

Question 4

Homologous series

Answer 4

Group of compounds with the same general formula

That share similar chemical properties

Question 5

Alkanes info

Answer 5

Part of the homologous series that only contains carbon and hydrogen

General formula: CnH2n+2

Question 6

Functional group

Answer 6

Molecules in the same homologous series have the same functional group

Group of atoms that determine how a compound reacts

Question 7

General formula of alkenes

Answer 7

CnH2n

Question 8

Crude oil

Answer 8

Longer hydrocarbons have high boiling points

Shorter hydrocarbons have low boiling points

Question 9

Saturated hydrocarbons

Answer 9

Contain single bonds

Question 10

Unsaturated hydrocarbons

Answer 10

Have double or triple bonds

Question 11

Refinery gas use

Answer 11

Domestic heating and cooking

3 and under chain

Question 12

Gasoline use

Answer 12

Fuel in cars

8 and under chain

Question 13

Kerosene use

Answer 13

Fuel in aircraft

15 and under chain

Question 14

Diesel use

Answer 14

Some cars, large vehicles, trains

20 and under chain

Question 15

Fuel oil use

Answer 15

Large ships, power stations

40 and under chain

Question 16

Bitumen use

Answer 16

Road surfaces, roofs

70+ chain

Question 17

Cracking

Answer 17

Splitting up long chain hydrocarbons

Long chain - high boiling point and are viscous

Shorter chain - thinner and paler, more demand for them

Because of the demand, long chain hydrocarbons are broken into short chain molecules using cracking
Cracking also produces alkenes

Question 18

Conditions for cracking

Answer 18

600-700 degrees

Silica or alumina are used as catalyst

Question 19

Burning hydrocarbons

Answer 19

Combustion reaction as the substance reacts with oxygen

Hydrocarbon + oxygen —> carbon dioxide + water

Question 20

Incomplete combustion

Answer 20

When there is a lack of oxygen

Carbon monoxide and soot produced.

CO stops the red blood cells carrying oxygen round the body.
Soot is trapped in the ozone layer and absorbs sun light, contributing to global dimming

Question 21

Acid rain

Answer 21

When fuels are burnt they produce sulfur dioxide and nitrogen oxides

Sulfur dioxides come from sulfur impurities in the air
And nitrogen oxides are created when the temp is high enough for nitrogen and oxygen to react
When they mix with water vapour they form dilute sulphuric acid and nitric acid
This forms acid rain

Question 22

Alkanes

Answer 22

Alkanes are saturated hydrocarbons
CnH2n+2

Alkanes burn in combustion

Halogens react with alkanes to make haloalkanes in the presence of UV light in substitution reaction with eg hydrogen bromide as an extra product

Question 23

Alkenes

Answer 23

Hydrocarbons with a double bond
CnH2n
Halogens react with alkenes to form HaloALKANES

Question 24

Halogen reaction with alkenes

Answer 24

This is addition reaction because the double carbon bond is split and halogen is added

Bromine and alkenes is used to test for carbon to carbon double bonds. Shake alkene with orange bromine water it will go colourless in the presence of an alkene

Question 25

Alcohol

Answer 25

OH functional group CnH2n+1OH When they are oxidised they form carboxylic acids When alcohols are burnt in enough oxygen they undergo complete combustion and produce water + carbon dioxide

Question 26

Production of ethanol

Answer 26

Ethanol is produced when ethene reacts with steam This is an addition reaction It’s needs a temp of 300 degrees and 60-70 atmospheres I’d pressure Phosphoric acid is used as a catalyst Cheap process - good yield But crude oil is a non renewable resource which will start running out and will become more expensive

Question 27

Ethanol can be produced by fermentation

Answer 27

Made from sugar which goes C6H12O6 glucose Happens at 30 degrees No oxygen Renewable But isn’t very concentrated

Question 28

Carboxylic acids

Answer 28

COOH functional group They react like other acids eg with salt Vinegar contains carboxylic acids Ethanol + oxygen —> ethanoic acid + water

Question 29

Esters

Answer 29

COO functional group Formed from an alcohol and carboxylic acid Acid catalyst usually used Ending is “oate” Alcohol forms first part, acid the second part of name Eg methanol + propanoic acid —> methyl propanoate + water Esters often make perfumes or food flavourings because they are volatile

Question 30

Addition polymers

Answer 30

Polymers are substances of high average relative molecular mass made up of small repeating units called monomers. These monomers have a double covalent bond (Unsaturated) but they can open up their carbon to carbon double bonds to form polymer chains. ``` Name comes from type of monomer Eg poly(propene) (C3H6)n ```

Question 31

Features of addition polymers

Answer 31

Most are inert - don’t react easily because the C — C bonds don’t break easily Takes ages for them to biodegrade Burning plastics can release toxic gases

Question 32

Polyesters - condensation polymerisation

Answer 32

Usually involves two types of monomer they react together and form bonds between them, making polymer chains. Each monomer must contain two functional groups and these (on either end) react with the functional group of other monomers creating long alternating monomers. For each new bond a small molecule eg water is lost