fuels and hydrocarbons

Question 1

hydrocarbon definition

Answer 1

a compound containing only hydrogen and carbon

Question 2

order (bottom to top) and uses of fractions in a fractionating column

Answer 2

bitumen: used to surface roads and roofs
fuel oil: fuel for large ships and some power stations
diesel oil: fuel for cars and some trains
kerosene: aircraft fuel
petrol: car fuel
natural gases: domestic heating and cooking

Question 3

petrol, kerosene and diesel definition

Answer 3

non-renewable fossil fuels obtained from crude oil

Question 4

methane definition

Answer 4

non-renewable fossil fuel found in natural gas

Question 5

describe a homologous series

Answer 5

• same general formula
• differ by CH2 in molecular formula from neighbouring compounds
• similar chemical properties
• gradual variation in physical properties

Question 6

complete combustion of hydrocarbon fuels definition

Answer 6

a reaction in which carbon dioxide and water are produced and energy is given out

Question 7

why do members of the same homologous series have similar reactions

Answer 7

their molecules contain the same functional group

Question 8

why is cracking necessary

Answer 8

allows for the production of smaller, more useful products from larger, less valuable ones. smaller chain hydrocarbons are easier to use and more in demand

Question 9

molecular formulae of alkanes 1-5

Answer 9

methane: CH4
ethane: C2H6
propane: C3H8
butane: C4H10
pentane: C5H12

Question 10

saturated hydrocarbon meaning

Answer 10

a hydrocarbon that only contains single bonds between atoms

Question 11

why are the alkanes saturated hydrocarbons

Answer 11

due to alkanes only containing single bonds

Question 12

molecular and structural formulae of alkanes 1-3

Answer 12

ethene: C2H4
propene: C3H6
but-1-ene: C4H8
but-2-ene: C4H8

Question 13

why is methene not possible

Answer 13

methene would only contain one carbon atom, but alkenes need to contain the functional group C = C, thus requiring a minimum of 2 carbon atoms

Question 14

why are alkenes unsaturated hydrocarbons

Answer 14

they must contain the functional group C = C, therefore containing a double bond and unsaturated hydrocarbons are those with 1 or more double bonds

Question 15

how to distinguish between alkanes and alkenes

Answer 15

using bromine water. mix bromine water and the hydrocarbon. will turn colourless if alkene but remain brown if alkane.

Question 16

polymer definition

Answer 16

substance of high average relative molecular mass made up of small repeating units

Question 17

how are the uses of polyethene related to its properties

Answer 17

flexible, strong, waterproof, chemically resistant - bottles, bags, food containers

Question 18

how are the uses of polypropene related to its properties

Answer 18

lightweight, resistant, strong - ropes, carpet

Question 19

how are the uses of polychloroethene related to its properties

Answer 19

electrical polyethene - pipes, windowsills, packaging

Question 20

how are the uses of polytetrafluoroethene related to its properties

Answer 20

slippery, unreactive - coating for non-stick pans, containers

Question 21

problems with polymers

Answer 21

• availability of starting materials
• persistence in landfill
• gases produced during combustion
• need to be sorted to be recycled

Question 22

advantages of recycling polymers

Answer 22

reduces landfill, conserves starting/natural materials, reduce greenhouse gases

Question 23

disadvantages of recycling polymers

Answer 23

time consuming to sort them, expensive