M. RahmanC1 TOPIC 5

1) Alkanes are…a)saturated hydrocarbon compoundsb)used to make polymer chainsc) toxic substancesd)unsaturated hydrocarbon compounds

Answers

a) saturated hydrocarbon compounds

M. RahmanC1 TOPIC 5

2) The chemical formula of propane is…a) C4H8

b) C2H6

c) C3H8

d) C3H6

•  

Answers

c) C3H8

M. RahmanC1 TOPIC 5

3) Which substance is used to distinguish between alkanes and alkenes?

Answers

bromine water

M. RahmanC1 TOPIC 5

4) Cracking involves the breaking down of…a) alkenes into alkanesb) large unsaturated hydrocarbon molecules into smaller, more useful, unsaturated

hydrocarbonsc) large saturated hydrocarbon molecules into smaller, more useful alkanes, along with some

alkenesd) alcohols into alkenes

Answers

C) large saturated hydrocarbon molecules into smaller, more useful alkanes, along with some alkenes

M. RahmanC1 TOPIC 5

5) The chemical formula of ethene is…a) C2H2

b) C2H4

c) C2H6

d) C3H6

Answers

b) C2H4

M. RahmanC1 TOPIC 5

6) Which one of the following compounds is unsaturated?

a)C4H8, b) C2H6, c) C3H8 d) C4H10

Answers.

a) C4H8,

M. RahmanC1 TOPIC 5

7) Many ethene molecules combine together to make…

a) ethaneb) poly(propane)c) poly(ethane)d) poly(ethene)

Answers

d) poly(ethene)

M. RahmanC1 TOPIC 5

8) The polymer called poly(chloroethene) is also known as…a) poly(ethane)b) PVCc) poly(propene)d) PTFE

Answers.

b) PVC

M. RahmanC1 TOPIC 5

9) Small molecules that join together to make polymers are called…

Answers.

Monomers

M. RahmanC1 TOPIC 5

10) Which one of the following is not a sensible way of reducing the amount of polymers entering landfill sites?

a) recyclingb) incinerationc) reusingd) fractional distillation

Answers

d) fractional distillation

M. RahmanC1 TOPIC 5

11) Describe how bromine is used to distinguish between alkenes and alkanes (3)Answers

• Bromine water is brown. • When alkenes are added it turns

colourless• When alkanes are added it remains brown

M. RahmanC1 TOPIC 5

12) What is the difference between unsaturated and saturated (2).

Answers

• Saturated contains no double bonds (alkanes)

• Unsaturated contains atleast one double bond (alkenes).

M. RahmanC1 TOPIC 5

13) Name the first 4 alkanes (2)

AnswersMethane EthanePropaneButane

M. RahmanC1 TOPIC 5

14) How many carbons does propane have?

Answers

3

M. RahmanC1 TOPIC 5

15) What are the conditions for cracking?

AnswersHeatCatalyst

M. RahmanC1 TOPIC 5

16) What are some of the biggest problems with polymers?

Answers• Non-biodegradable-don’t rot• They remain in landfill sites

for many years

M. RahmanC1 TOPIC 5

17) What are biodegradable polymers?

Answers.Made from starch molecules (natural) so when buried they are broken down by microorganisms.

M. RahmanC1 TOPIC 5

18) What are photodegradable polymers?

Answers.

Polymers that break down in sunlight.

M. RahmanC1 TOPIC 5

19) How are the products of crude oil separated. a) Crackingb) Fractional distillationc) Thermal decomposition

Answers

b) Fractional distillation

M. RahmanC1 TOPIC 5

20) In fractional distillation of crude oil which one of these comes off at the top of the column a) Gases b) bitumen c) Petrold) Kerosene

Answers

a) Gases

M. RahmanC1 TOPIC 5

21*) In fractional distillation of crude oil at the top of the column the following molecules come off. a) High boiling point, low viscosity, highly flammable hydrocarbon b) Low boiling point, low viscosity, highly flammable hydrocarbon c) High boiling point, low viscosity, low flammable hydrocarbon

Answers

b) Low boiling point, low viscosity, highly flammable hydrocarbon

M. RahmanC1 TOPIC 5

22) The larger the hydrocarbon..a) The higher the boiling pointb) The lower the boiling pointAnswers

a) The higher the boiling point

M. RahmanC1 TOPIC 5

23) What are the products of the complete combustion of hydrocarbon?

Answers

Carbon dioxide + water

M. RahmanC1 TOPIC 5

24) When does incomplete combustion take place?

Answers

When there is a lack of oxygen-ie when gas heaters are not well ventilated.

M. RahmanC1 TOPIC 5

25) Why is incomplete combustion unsafe?

Answers

It produces a odourless gas called carbon monoxide which is poisonous.

M. RahmanC1 TOPIC 5

26) What are the four things that need to be considered when choosing the best fuel?Answers

a) Ease of ignitionb) Amount of energy releasedc) Amount of smoke and ash produced.d) How easy it is to store and transport.

M. RahmanC1 TOPIC 5

27) How is acid rain formed?

Answers• Sulphur impurities in fossil

fuels burn in oxygen to produce Sulphur dioxide.• Sulphur dioxide reacts with

rain water to produce acid rain

M. RahmanC1 TOPIC 5

28) What are the problems with acid rain? (3)

Answers• Lakes become acidic-plants

and animals die• Kills trees• damages limestone buildings

and statues.

M. RahmanC1 TOPIC 5

29) List three ways of reducing acid rain? (3)

Answers• Line chimneys of power stations with

alkali-neutralises acidic gases before released into the atmosphere.

• Sulphur removed from fuels before they are burnt-low sulphur petrol.

• Reduce use of fossil fuels.

M. RahmanC1 TOPIC 5

30) Give the name of the three main green house gases and explain how they cause the earth to heat-up (3)

Answers.Carbon dioxideMethaneWater vapour.They act like a blanket above the earth atmosphere to (trap) AND re-radiate back to earth

M. RahmanC1 TOPIC 5

31) Explain how iron seeding is used to reduce carbon dioxide levels (3).

Answers.• Iron is needed by plants for

photosynthesis.• Injecting iron into oceans

promotes phytoplankton growth.• Phytoplankton absorb carbon

dioxide from the atmosphere.

M. RahmanC1 TOPIC 5

32*) Explain how carbon capture is used to reduce carbon dioxide levels (3).Answers.• This involves converting waste CO2 to useful

hydrocarbons.• Short chain hydrocarbon are easy to make but

longer chains (needed for petrol) are more difficult to produce)

(Require, high temperature and pressure and a catalyst)

M. RahmanC1 TOPIC 5

33*) What is biogas ?

Answers.Produced by microorganism which decompose living organism waste/dead plants which is used as fuel.

M. RahmanC1 TOPIC 5

34*) What is bioethanol ?

Answers.• Sugar cane and sugar beet can

be used as sources of sugar.• The sugars are then fermented

by using yeast to produce ethanol which is used as fuel.

M. RahmanC1 TOPIC 5

35) Name four advantages of using biofuel?

Answers.• They are clean fuel and does not produce

carbon particulates• They are renewable• They are carbon neutral and add less

carbon dioxide to the atmosphere compared to fossil fuels.

• Less crude oil is used as fuel and so the reserves will last longer.

M. RahmanC1 TOPIC 5

36) Name four disadvantages of using biofuel?

Answers.• Land is needed to grow biofuels and so there is

less land available for growing food and for homes.• This may lead to a shortage of food and food

prices rising• Lots of crops required to provide a small amount of bio-

methane• When making biofuels energy is needed to transport the

crops and to fertilise the crops.• Bad season reduces availability of biofuels.

M. RahmanC1 TOPIC 5

37) Which gases do fuel cells combine to produce energy?

Answers.Hydrogen and Oxygen

M. RahmanC1 TOPIC 5

38) List 5 advantages of fuel cells?

Answers.• They are much more efficient than batteries or

power station• Electricity is directly produced from the

reactions so no turbines are needed.• Don’t produce CO2-so don’t contribute global

warming• Don’t release SO2-don’t contribute to acid rain.• Only by-product is water-which is harmless.

M. RahmanC1 TOPIC 5

39)What are the major disadvantages of fuel cells?

Answers.• A lot of energy is needed to make

Hydrogen from water in the first place. This means burning fossil fuels is required, but to a smaller extent.

• Hydrogen is both highly explosive and flammable, so transport and storage can be a problem.