Organic Chem

Question 1

The form of a alkanes and alkenes

Answer 1

The alkanes form a homologous series

Question 2

Properties of homologous series? (4)

Answer 2

have the same general formula

differ by CH2 in molecular formulae from neighbouring members of the series

show a gradual variation in physical properties, such as their boiling points

have similar chemical properties

Question 3

Formula for alkenes and alkanes

Answer 3

CnH2n+2

Question 4

What are alkanes?

Answer 4

saturated hydrocarbons:

Question 5

Why are alkanes saturated?

Answer 5

because their carbon atoms are joined together by single bonds

Question 6

Why are alkanes hydrocarbons?

Answer 6

because they are compounds containing hydrogen and carbon only

Question 7

molecular formula for methane, ethane, propane, butane?

Answer 7

1. CH4
2. C2H6
3. C3H8
4. C4H10

Question 8

Know how to draw the display formula for methane, ethane, propane, butane?

Question 9

molecular formula for ethene, propene, butene, pentene?

Answer 9

1. C2H4
2. C3H6
3. C4H8
4. C5H10

Question 10

Know how to draw the display formula for ethene, propene, butene, pentene?

Question 11

structural formula for methane, ethane, propane, butane?

Answer 11

1. CH4
2. CH3 CH3
3. CH3 CH2 CH3
4. CH3 CH2 CH2 CH3

Question 12

structural formula for ethene, propene, butene, pentene?

Answer 12

1. CH2 CH2
2. CH2 CH CH3
3. CH2 CH CH2 CH3
4. CH2 CH CH2 CH2 CH3

Question 13

Isomers?

Answer 13

= are compounds with the same molecular formula but different structural or displayed formula

Question 14

Example of isomers?

Answer 14

butane and methylpropane

Question 15

What do Alkanesandalkenesboth undergo?

Answer 15

Alkanesandalkenesboth undergocomplete combustion, but only alkenes can undergoaddition reactions.

Question 16

Complete combustion?

Answer 16

The complete combustion of alkanes and alkenes involves theoxidationofhydrocarbons.

Question 17

Addition reactions of alkenes

Answer 17

Thefunctional group, C=C, allows alkenes to undergo addition reactions. where the double bond is removed?

Question 18

Distinguishing between alkanes and alkenes what is solution?

Answer 18

orange-brown solution of bromine dissolved in water, called bromine water

Question 19

what happens when bromine water is mixed with an alkane?

Answer 19

there is no change when bromine water is mixed with an alkane

Question 20

what happens when bromine water is mixed with an alkene?

Answer 20

the bromine water becomes colourless when it is mixed with an alkene

Question 21

What is a polymer?

Answer 21

larger molecule made up by joining small monomers together

Question 22

key feature when drawing a polymer?

Answer 22

Line must go through the bracket

Question 23

Problems with polymers?

Answer 23

are not biodegradable

Question 24

What happens to a polymer at the end of it life (3)

Answer 24

1. Landfill
2. Ocean
3. Recycled

Question 25

Landfill pros (2) and cons (3)

Answer 25

+ Keeping all in 1 place + Cheap - Lots of space - Not biodegradable - Smell

Question 26

Burning pros (3) and cons (2)

Answer 26

+ Gets rid of plastic + We can burn it and use the energy + Little space - Produce co2 - Produce toxic gases

Question 27

Recycled pros (1) and cons (1)

Answer 27

+ Avoid landfill and toxic gases - Time consuming

Question 28

What is cracking?

Answer 28

Cracking is a reaction in which larger hydrocarbon molecules are broken down into smaller, more useful hydrocarbon molecules, some of which are unsaturated:

Question 29

What is starting of cracking? (alkene or alkane)

Answer 29

Alkane

Question 30

Conditions needed for cracking? (2)

Answer 30

- 600C - 700C - Catalyst e.g silicone dioxide or aluminium oxide

Question 31

Cracking is important for two main reasons (2)

Answer 31

1. it helps to match the supply of fractions with the demand for them 2. it produces alkenes, which are useful as feedstock for the petrochemical industry