Organic Chemistry

Question 1

homologous series

Answer 1

family of similar compounds

Question 2

functional groups

Answer 2

atom/ group of atoms that determines the chemical properties of the compound

Question 3

general formulae of alkenes

Answer 3

CnH2n

Question 4

general formulae of alkanes

Answer 4

CnH2n+2

Question 5

are alkenes saturated or unsaturated

Answer 5

unsaturated

Question 6

are alkanes saturated or unsaturated

Answer 6

saturated

Question 7

as chain length increases…

Answer 7

• intermolecular forces between molecules become stronger
• melting and boiling point increase
• viscosity increases
• volatility decreases

Question 8

condition for alkanes and chlorine to react

Answer 8

UV light

Question 9

bromine and alkenes reaction

Answer 9

orange to colourless

Question 10

bromine with alkanes reaction

Answer 10

stays orange

Question 11

what are fuels

Answer 11

chemical substance that releases energy when burned

Question 12

main fossil fuels

Answer 12

natural gas, petroleum, coal

Question 13

main component of natural gas

Answer 13

methane

Question 14

what is a hydrocarbon

Answer 14

compound made up of hydrogen and carbon atoms only

Question 15

process of frac. distillation of petroleum

Answer 15

• petroleum is heated and pumped into bottom of distillation fraction
• molecules with less carbon atoms have lower boiling points and evaporate first and rise
• the top is much cooler, so it will condense back into a liquid and is collected
• hydrocarbons with more carbon atoms have higher boiling point, it condenses at a higher temp., midway along the tower and is collected

Question 16

what is a fraction

Answer 16

group of hydrocarbons with similar chain length

Question 17

fractions list

Answer 17

• refinery gas
• gasoline
• naphtha
• paraffin
• diesel oil
• fuel oil
• lubricating fraction
• bitumen

Question 18

refinery gas

Answer 18

bottles gases for cooking and heating

Question 19

gasoline

Answer 19

car fuel

Question 20

naphtha

Answer 20

starting point for chemical reactions

Question 21

paraffin/ kerosene

Answer 21

fuel for aircrafts, lamps and oil stoves

Question 22

diesel oil

Answer 22

fuel for diesel engines

Question 23

fuel oil

Answer 23

fuel for power stations, ships and home heating systems

Question 24

lubricating fraction

Answer 24

oil for car engines, machinery, waxes and polishes

Question 25

bitumen

Answer 25

road surfaces and roofs

Question 26

example of substitution reaction

Answer 26

alkanes and chlorine

Question 27

incomplete combustion

Answer 27

burns with lack of oxygen and produces poisonous carbon monoxide and soot

Question 28

why is carbon monoxide toxic

Answer 28

bind irreversibly to haemoglobin and prevents it from carrying oxygen

Question 29

substitution reaction

Answer 29

- atom(s) are replaced by different atom(s) - makes chloroalkanes - needs UV light to provide activation energy - photochemical reaction (needs light)

Question 30

cracking

Answer 30

- chemical process that breaks down longer chain alkane molecules into smaller alkane and alkene molecules (which are more useful)

Question 31

conditions for cracking

Answer 31

- catalyst - high temperature

Question 32

use for alkenes made from cracking

Answer 32

- fuels (flow and ignite more easily)

Question 33

reaction that makes one product

Answer 33

addition

Question 34

reaction with hydrogen and alkenes

Answer 34

hydrogenation (makes margarine)

Question 35

reaction with steam and alkenes

Answer 35

hydration (used as solvent or disinfectant)

Question 36

reaction with bromine and alkenes

Answer 36

brown --> colourless