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Organic chemistry Low demand 1 – Questions
Q1.Crude oil and natural gas are natural resources in many countries.
The table shows percentages of hydrocarbons in natural gas from three different countries.
HydrocarbonPercentage (%) of hydrocarbon in natural
gas
Country X Country Y Country Z
Methane 78.03 88.10 94.36
Ethane 9.70 5.30 2.37
Propane 4.82 2.16 0.15
Butane 1.33 0.72 0.02
Pentane 0.30 0.18 0.00
(a) Calculate the mean percentage of propane from countries X, Y and Z.
Give your answer to 2 decimal places.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Mean percentage of propane = ____________________ %(2)
(b) Suggest why natural gas from different countries has different percentages of hydrocarbons.
___________________________________________________________________
___________________________________________________________________(1)
(c) Complete the sentence.
Choose the answer from the box.
an atom an electron an ion a molecule
The formula CH4 represents ____________________ of methane.(1)
(d) Complete the sentence.
Page 1 of 41
The hydrocarbons in the table belong to the homologous series of
____________________ .(1)
Figure 1 shows how properties vary with the increasing size of molecule in this homologous series.
Figure 1
(e) Which graph shows how boiling points vary?
Tick one box.
A B C D
(1)
(f) Which graph shows how viscosity varies?
Tick one box.
A B C D
(1)
(g) Crude oil is fractionally distilled.
Fractions with larger molecules are cracked.
Describe two differences between fractional distillation and cracking.
1. _________________________________________________________________
___________________________________________________________________
2. _________________________________________________________________
___________________________________________________________________(2)
(h) Ethene is a product of crude oil.
Complete the sentence.
Ethene polymerises to produce ____________________ .
Page 2 of 41
(1)
(i) The production of plastic bags uses limited resources.
Figure 2 shows two ways (A and B) of saving limited resources.
Figure 2
Name A and B.
Choose the answers from the box.
recycle reduce release reuse reverse
A ____________________
B ____________________(2)
(Total 12 marks)
Q2.The apparatus in the figure below is used to separate a mixture of liquids in a fuel.
(a) What is apparatus W on above the figure above?
Tick one box.
Page 3 of 41
Beaker
Boiling Tube
Flask
Jug
(1)
(b) What is the name of this method of separation?
Tick one box.
Crystallisation
Electrolysis
Filtration
Distillation
(1)
(c) Name the changes of state taking place at A and B in the figure above.
Use words from the box.
boiling condensing freezing melting
Change of state at A: _________________________________________________
Change of state at B: _________________________________________________(2)
(d) Table 1 shows the boiling points of the hydrocarbons in the fuel.
Table 1
Hydrocarbon Boiling pointin °C
Pentane 36
Hexane 69
Heptane 98
Page 4 of 41
Octane 125
Which hydrocarbon will be the last to collect in the beaker?
Tick one box.
Pentane
Hexane
Heptane
Octane
(1)
(e) The fuel is a mixture of liquids that has been designed as a useful product.
What name is given to this type of mixture?
Tick one box.
Catalyst
Formulation
Polymer
Solvent
(1)
(f) Describe how this fuel is different from crude oil.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________(2)
(g) A student measured the melting point of a solid hydrocarbon four times.
The student’s results are in Table 2.
Table 2
Page 5 of 41
Trial 1 Trial 2 Trial 3 Trial 4
Melting point in °C 35 48 37 37
Calculate the mean melting point of the hydrocarbon, leaving out any anomalous result.
Give your answer to two significant figures.
___________________________________________________________________
___________________________________________________________________
Mean melting point = __________________ °C(2)
(Total 10 marks)
Q3.A student investigated the substances produced when fuels burn.
The figure below shows the apparatus the student used.
(a) The complete combustion of a hydrocarbon produces carbon dioxide and one other substance.
Look at the figure above. What would the student see in tube A?
___________________________________________________________________
___________________________________________________________________(1)
(b) When the student burned the fuel she saw soot in the funnel.
Explain why soot forms.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Page 6 of 41
___________________________________________________________________(2)
(c) The student burned another fuel which contained impurities.
The substance in tube B is water containing universal indicator.
The indicator turned red.
Which gas made the indicator turn red?
Tick one box.
Ammonia
Carbon monoxide
Nitrogen
Sulfur dioxide
(1)(Total 4 marks)
Q4.There are several different forms of carbon and many different carbon compounds.
(a) Figure 1 shows a 3D model of a molecule of methane (CH4).
Figure 1
Draw the 2D structure of a methane molecule.(1)
(b) Different forms of carbon have different bonding and structure.
Draw one line from the form of carbon to the bonding and structure.
Form of carbon Bonding and structure
Page 7 of 41
(3)
(c) Crude oil is a mixture of many different carbon compounds.
Crude oil can be separated into useful fractions by fractional distillation.
Figure 2 shows a column used to separate crude oil.
Figure 2
Page 8 of 41
Complete the sentences.
Use words from the box.
condense evaporate freeze
Crude oil is heated so that most of the compounds ____________________
At different temperatures the compounds cool and ____________________(2)
(d) Which fraction is the most viscous?
Tick one box.
Engine oil
Diesel oil
Kerosene
Petrol
(1)
(e) Which fraction is the most flammable?
Tick one box.
Diesel oil
Kerosene
Petrol
Refinery gas
(1)
(f) Why does kerosene separate out of the mixture before diesel oil?
___________________________________________________________________
___________________________________________________________________(1)
(Total 9 marks)
Page 9 of 41
Q5.A student investigated the viscosity of liquid hydrocarbons.
A viscous liquid is a liquid that flows slowly.
The student used this method.
• Measure 50 cm3 of the liquid hydrocarbon.
• Pour the liquid hydrocarbon into the funnel, as shown in Figure 1.
• Time how long it takes for all of the liquid hydrocarbon to run out of the funnel.
• Repeat the experiment for other liquid hydrocarbons.
(a) (i) Give the name of apparatus A in Figure 1.
______________________________________________________________(1)
(ii) Name the apparatus that could be used to measure 50 cm3 of liquid hydrocarbon.
______________________________________________________________(1)
(b) The student’s results for six liquid hydrocarbons are shown in Table 1.
Table 1
Formula of liquid hydrocarbon
Time for liquid hydrocarbon to run out of the funnel in seconds Mean time in
secondsExperiment 1 Experiment 2 Experiment 3
C5H12 12 11 13 12
C6H14 14 15 15 15
C7H16 19 20 18
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C8H18 27 26 28 27
C10H22 46 48 47
C12H26 65 67 69 67
(i) The student did the experiment three times with each liquid hydrocarbon.
Give two reasons why.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________(2)
(ii) Use the data in Table 1 to calculate the mean time, in seconds, for C7H16
______________________________________________________________
______________________________________________________________
Mean time = __________________ seconds(1)
(iii) Complete the sentence.
As the number of carbon atoms in a molecule of liquid hydrocarbon increases, the time taken for the liquid hydrocarbon to run out of the funnel
________________________ .(1)
(iv) A ring has been drawn around one result in Table 1.
This result has not been used to calculate the mean time for C10H22
Suggest why this result was not used.
______________________________________________________________
______________________________________________________________(1)
(v) Suggest one error the student may have made to get the ringed result.
______________________________________________________________
______________________________________________________________
______________________________________________________________(1)
Page 11 of 41
(c) The student investigated the effect of temperature on the viscosity of one of the liquid hydrocarbons.
The liquid hydrocarbon he was using had the hazard symbols shown in Figure 2.
(i) Suggest why the student warmed the liquid hydrocarbon using warm water and not a Bunsen flame.
______________________________________________________________
______________________________________________________________(1)
(ii) The student wore safety glasses.
Give one other safety precaution the student should take, and give a reason for this safety precaution.
Safety precaution _______________________________________________
Reason _______________________________________________________
______________________________________________________________(2)
(d) This is the method the student used to investigate the effect of temperature on the viscosity of one of the liquid hydrocarbons.
• Measure 50 cm3 of the liquid hydrocarbon and pour it into a beaker.
• Stand the beaker of liquid hydrocarbon in a heated water bath.
• Leave for a few minutes.
• Measure the temperature of the liquid hydrocarbon.
• Pour the liquid hydrocarbon into the funnel, as shown in Figure 3.
Page 12 of 41
• Time how long it takes for all of the liquid hydrocarbon to run out of the funnel.
• Repeat the experiment at different temperatures.
(i) The student’s results are shown in Table 2.
Table 2
Temperature of liquid hydrocarbon
in °C
Time to run out of the funnel in seconds
23 27
30 21
37 17
46 16
55 11
65 9
Plot the results shown in Table 2 on the graph in Figure 4.
Draw a curve of best fit.
Page 13 of 41
(3)
(ii) One of the points is anomalous.
Draw a ring around the anomalous point on your graph.(1)
(iii) Predict how long it will take the liquid hydrocarbon to run through the funnel at 70 °C.
Show your working on your graph.
Time = ____________________ seconds(2)
(iv) Describe the relationship between the temperature of the liquid hydrocarbon and the viscosity of the liquid hydrocarbon.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________(3)
(v) The apparatus the student used in Figure 2 could lead to a systematic error in the results.
Identify one source of systematic error, and describe how the student could avoid or reduce the error.
______________________________________________________________
______________________________________________________________
______________________________________________________________
Page 14 of 41
______________________________________________________________(2)
(Total 22 marks)
Q6.Crude oil is a fossil fuel.
(a) To make crude oil more useful it is separated into fractions.
Use the correct word from the box to complete each sentence.
boiling compound decomposition distillation
filtration mixture molecule
(i) Crude oil is a _________________________ of different substances.(1)
(ii) The substances in crude oil have different
_________________________ points.(1)
(iii) Crude oil is separated by fractional _________________________ .(1)
(b) Petrol is one of the fractions produced from crude oil.
Car engines use a mixture of petrol and air.
The diagram shows some of the gases produced.
(i) What type of reaction happens to petrol in a car engine?
Tick ( ) one box.
combustion
decomposition
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neutralisation
(1)
(ii) Petrol contains octane (C8H18).
Complete the word equation for the reaction of octane with oxygen.
octane + ______________ ______________ + ______________(2)
(iii) Cars use sulfur-free petrol as a fuel.
Describe why sulfur should be removed from petrol.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________(2)
(c) Some fractions from crude oil contain large hydrocarbon molecules.
These molecules can be cracked to produce smaller, more useful molecules.
An equation for cracking decane is:
C10H22 C3H8 + C2H4 + C5H10
decane propane ethene pentene
(i) Why is propane useful?
Tick ( ) one box.
Propane is a polymer.
Propane is an alloy.
Propane is a fuel.
(1)
(ii) Draw bonds to complete the displayed structure of ethene.
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(1)
(iii) What is the colour change when bromine water reacts with ethene?
Tick ( ) one box.
Orange to colourless
Orange to green
Orange to red
(1)
(iv) Complete the sentence.
Pentene is useful because many pentene molecules can join together
to form _________________________ .(1)
(Total 12 marks)
Q7.The diagram shows a carbon atom.
(a) (i) A proton is labelled.
Use the correct answer from the box to label each of the other sub-atomic particles.
Page 17 of 41
electron ion molecule neutron
(2)
(ii) The atom of carbon is represented as:
What is the mass number of this carbon atom?
Draw a ring around the correct answer.
6 13 19(1)
(iii) Complete the sentence.
Atoms of carbon have no overall electrical charge because the number
of protons is the same as the number of _______________________ .(1)
(b) Butane is represented as:
(i) Use the correct answer from the box to complete each sentence.
bond compound helium hydrogen mixture oxygen
Butane is a ___________________ .
Butane contains atoms of carbon and ___________________ .
Each line between the atoms in butane represents a chemical
_________________ .(3)
(ii) Which is the correct formula for butane?
Tick (✔) one box.
C4H4
C4H8
Page 18 of 41
C4H10
(1)(Total 8 marks)
Q8.Energy is released by burning fuels.
(a) The bar chart shows the energy in kilojoules, kJ, released by burning 1 g of five different fuels.
(i) Which fuel releases least energy by burning 1 g?
______________________________________________________________(1)
(ii) How much energy is released by burning 1 g of coal?
Energy = _________________________kJ(1)
(iii) Calculate the mass of petrol that will release the same amount of energy as 1 g of hydrogen.
Use information from the bar chart to help you.
______________________________________________________________
______________________________________________________________
Page 19 of 41
Mass = __________________ g(1)
(b) Coal burns in oxygen and produces the gases shown in the table.
Name Formula
Carbon dioxide CO2
Water vapour H2O
Sulfur dioxide SO2
Use information from the table to name one element that is in coal.
___________________________________________________________________(1)
(c) Hydrogen can be made from fossil fuels.Hydrogen burns rapidly in oxygen to produce water only.
A lighthouse uses electricity generated by burning hydrogen.
Suggest two advantages of using hydrogen as a fuel.
Use information from the bar chart and the diagram above to help you.
1. _________________________________________________________________
___________________________________________________________________
2. _________________________________________________________________
___________________________________________________________________(2)
(Total 6 marks)
Page 20 of 41
Q9.Alkanes are hydrocarbons found in crude oil.
(a) (i) Complete the sentence.
Hydrocarbons contain the elements _____________ and _____________only.
(1)
(ii) Ethane is an alkane with the formula C2H6
Draw a ring around the correct answer to complete the sentence.
Alkanes are hydrocarbons with the general formula
CnHn
CnH2n
CnH2n+2
(1)
(b) Crude oil is separated into useful fractions by fractional distillation.
Describe and explain how crude oil is separated into fractions by fractional distillation.
Use the diagram to help you answer the question.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Page 21 of 41
___________________________________________________________________
___________________________________________________________________(4)
(c) Dodecane (C12H26) from crude oil is cracked to produce ethene (C2H4).
(i) Complete the equation for this reaction.
C12H26 2 C2H4 + ______________(1)
(ii) Give two conditions needed for cracking.
1. ____________________________________________________________
2. ____________________________________________________________(2)
(Total 9 marks)
Q10.Barbecues are heated by burning charcoal or burning hydrocarbons.
(a) Use the Chemistry Data Sheet to help you to answer this question.
The chemical equation for charcoal burning is:
C + O2 CO2
Complete the word equation for this reaction.
carbon + __________________ carbon dioxide(1)
(b) Propane is a hydrocarbon.
(i) Complete the displayed structure of propane. Draw in the missing bonds.
Page 22 of 41
(1)
(ii) Write the chemical formula of propane._________________________(1)
(iii) Draw a ring around the correct answer to complete the sentence.
hydrogen.
Propane burns in air to produce carbon dioxide and hydroxide.
water.
(1)
(c) The table shows information about six hydrocarbons.
Hydrocarbon State at roomtemperature (20°C) Boiling point in °C
Ethane (C2H6) gas −89
Ethene (C2H4) gas −104
Butane (C4H10) gas −1
Butene (C4H8) gas −6
Hexane (C6H14) liquid +69
Hexene (C6H12) liquid +64
Tick ( ) two correct statements about the six hydrocarbons.
Statement Tick ( )
Ethane and butane boil at temperatures less than 20°C.
Hexene and butene are alkanes.
Butane and hexane are liquid at 0°C.
Ethene and hexene each have a carbon-carbon double bond.
(2)(Total 6 marks)
Page 23 of 41
Q11.(a) Crude oil is a mixture of compounds.
These compounds are made up of hydrogen and carbon atoms only.
(i) Draw a ring around the correct answer to complete the sentence.
Compounds made up of carbon and hydrogen atoms only
alcohols.
are called hydrocarbons.
vegetable oils.
(1)
(ii) The table shows five of these compounds.
Compound State at room temperature (20 °C) Boiling point in °C
ethane, C2H6 gas – 89
butane, C4H10 gas 0
hexane, C6H14 liquid +69
pentadecane, C15H32 liquid +270
heptadecane, C17H36 solid +302
Tick ( ) two correct statements about the five compounds.
Statement Tick ( )
ethane has the smallest molecules
hexane and pentadecane are liquid at 100 °C
heptadecane has the highest boiling point
butane boils at 100 °C
(2)
(iii) Draw a ring around the correct answer to complete each sentence.
Fractional distillation is used to separate the compounds in crude oil.
cracking
The first step in fractional distillation is displacing the crude oil.
evaporating
Page 24 of 41
burn
During fractional distillation the compounds
condense
decompose
at different temperatures.(2)
(b) Steam distillation is used to separate oils from plants.
The diagram shows some apparatus that can be used to separate oil from lavender plants. Four parts of the apparatus are labelled W, X, Y and Z.
(i) In which part, W, X, Y or Z, of the apparatus:
is steam produced
are steam and oil condensed?
(2)
(ii) Use the correct word from the box to complete the sentence.
dissolves floats sinks
When the oil separates from the water, the oil ___________________(1)
(iii) Describe how part Z of the apparatus can be used to remove the water from the oil.
Page 25 of 41
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________(2)
(Total 10 marks)
Q12.About 3000 million years ago carbon dioxide was one of the main gases in the Earth’s early atmosphere.
About 400 million years agoplants and trees grew on mostof the land. When the plantsand trees died they werecovered by sand and slowlydecayed to form coal.
Today coal is burned in powerstations to release the energyneeded by industry.
(a) The bar chart shows the percentage of some of the elements in this coal.
Page 26 of 41
(i) This coal contains 85 % carbon. Draw the bar for carbon on the chart.(1)
(ii) Coal is burned in the atmosphere to release energy.Two of the products of burning coal are shown.
Draw one line from each product to its environmental impact.
Product Environmental impact
Acid rain
Sulfur dioxide
Global dimming
Carbon particles
Global warming
(2)
(b) Use the information above and your knowledge and understanding to answer these questions.
(i) How did the formation of coal decrease the amount of carbon dioxide in the Earth’s early atmosphere?
Page 27 of 41
______________________________________________________________
______________________________________________________________(1)
(ii) How does burning coal affect the amount of carbon dioxide in the Earth’s atmosphere?Explain your answer.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________(2)
(Total 6 marks)
Q13.Crude oil is a mixture of hydrocarbons.Crude oil can be separated into fractions.
(a) (i) Complete the sentence.
The process used to separate the crude oil into fractions is called
fractional ______________________________ .(1)
(ii) Why do the fractions separate at different temperatures?
______________________________________________________________
______________________________________________________________(1)
Page 28 of 41
(b) Tick ( ) two properties of fraction 6.
Property Tick ( )
contains hydrocarbons
has a small number of carbon atoms in each molecule
is easy to ignite
has a high boiling point
(2)
(c) Fraction 1 contains hydrocarbons called alkanes.The general formula of an alkane is: CnH2n+2
What is the formula of the alkane that has 5 carbon atoms in each molecule?
Draw a ring around the correct answer.
C5H9 C5H10 C5H11 C5H12
(1)(Total 5 marks)
Q14.Natural gas is mainly a hydrocarbon called methane.
(a) Use one word from the box to complete the sentence.
compounds elements molecules
Hydrocarbons contain hydrogen and carbon only.
Hydrogen and carbon are _____________________________________________ .(1)
(b) The diagrams represent atoms of hydrogen and carbon.
Page 29 of 41
Draw a ring around the correct answer to complete the sentences.
bond.
(i) The centre of each atom is called the nucleus.
symbol.
(1)
three
(ii) The hydrogen atom has one electron and the carbon atom has four electrons.
six
(1)
(c) A molecule of methane can be represented as
Draw a ring around the correct answer to complete the sentences.
CH
(i) The formula of methane is CH4
C4H4
(1)
bond.
(ii) The line between C—H is called a molecule.
nucleus.
(1)
(d) Methane burns to produce carbon dioxide (CO2) and water (H2O).
(i) Draw a ring around the correct answer to complete the sentence.
carbon.
When methane burns it reacts with nitrogen.
oxygen.
(1)
Page 30 of 41
(ii) Hydrogen (H2) can be used as a fuel.
Suggest why burning hydrogen would be less harmful to the environment than burning methane.
______________________________________________________________
______________________________________________________________(1)
(Total 7 marks)
Q15.Crude oil is a natural resource from which useful fuels can be separated.
(a) Crude oil is a mixture of hydrocarbons.
Complete the sentence about a hydrocarbon molecule.
A hydrocarbon molecule is made up of ____________________ and carbon atoms only.
(1)
(b) Many fuels come from crude oil. Some of these fuels are shown in the diagram.
Suggest two properties of these fuels that allow them to be separated from crude oil.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________(2)
Page 31 of 41
(c) Fuels from crude oil burn to provide heat energy.
When a fuel burns, it combines with oxygen in the air and produces carbon dioxide and water. When there is not enough oxygen, the fuel burns and also produces carbon monoxide and carbon particles.
Draw a straight line from each substance that links it to a possible environmental problem.
One has been done for you.
(3)
(Total 6 marks)
Q16.(a) Complete this sentence about crude oil.
Crude oil is mainly a mixture of compounds called ___________________ which contain carbon and hydrogen only.
(1)
(b) The diagram shows a laboratory experiment used to separate crude oil.
Page 32 of 41
Complete each sentence by choosing the correct words from the box.
condensation distillation evaporation
melting sublimation
The main process taking place at A is _________________________________
The main process taking place at B is _________________________________
This method of separating crude oil is called ____________________________(3)
(c) Complete this sentence by crossing out the word in each box that is wrong. The first one has been done for you.
This method of separating crude oil works because the the molecules are,
the their boiling point and the volatile they are.(1)
(Total 5 marks)
Q17.Petrol is a hydrocarbon fuel.
(a) Complete this sentence.
Hydrocarbons are compounds which are made from the elements _____________
and ____________________ only.
Page 33 of 41
(2)
(b) This apparatus was used to study the combustion of a hydrocarbon fuel.
(i) Name the substance which changed the anhydrous copper sulphate from white to blue.
______________________________________________________________(1)
(ii) Carbon dioxide is also produced when the hydrocarbon fuel is burned.Name the solution, labelled X on the diagram, which tests for carbon dioxide.
______________________________________________________________(1)
(iii) Complete this sentence.
Carbon dioxide turns solution X ______________________________________ .(1)
(c) The graph shows how the concentration of carbon dioxide in the air has varied since the year 1000.
Page 34 of 41
(i) Describe the changes in the concentration of carbon dioxide in the air since the year 1000.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________(3)
(ii) Suggest why the concentration of carbon dioxide in the air has changed since the year 1800.
______________________________________________________________
______________________________________________________________(1)
(Total 9 marks)
Q18.Some gas cookers burn natural gas, methane. Methane, CH4, is a hydrocarbon.
Page 35 of 41
(a) What is meant by hydrocarbon?
___________________________________________________________________
___________________________________________________________________(2)
(b) When methane burns there must be a good supply of air.
(i) Complete the word equation by choosing the correct two chemicals from the box.
carbon dioxide hydrogen oxygen water
methane + oxygen → ____________________ + ______________________(2)
(ii) Without a good supply of air, carbon monoxide is formed. Why is carbon monoxide a dangerous gas?
______________________________________________________________
______________________________________________________________(1)
(Total 5 marks)
Q19.Fractional distillation is used to separate fractions in the crude oil mixture.
(a) Draw a line to join each fraction to its use as a fuel. One line has been drawn for you.
Page 36 of 41
(2)
(b) (i) Why does petrol separate from the other fractions in the crude oil mixture?
______________________________________________________________
______________________________________________________________(1)
(ii) Petrol contains the elements carbon and hydrogen only.
Which two of the substances in the diagram are formed when petrol burns?
1. ____________________________________________________________
2. ____________________________________________________________(2)
Page 37 of 41
(Total 5 marks)
Q20.The table shows some information about alkanes.
Name Formula Relative formula mass Boiling point in °C
methane CH4 16 –160
ethane C2H6 30 –90
propane 44 –40
butane C4H10 58
pentane C5H12 72 36
hexane C6H14 86 68
(a) Give the formula of propane.
___________________________________________________________________(1)
(b) (i) What happens to the boiling points of the alkanes as the relative formula mass increases?
______________________________________________________________(1)
(ii) Draw a graph. Plot the points and draw a best fit line.
Page 38 of 41
(3)
(iii) What is the boiling point of butane?
______________________________________________________________(1)
(iv) Show clearly on the graph how you found the boiling point of butane.(1)
(c) Circle which of the following is not an alkane.
C71116 C9H18 C11H24 C24H50
(1)(Total 8 marks)
Q21.Hot air balloons are used mainly for pleasure trips.
Page 39 of 41
(a) Air is a mixture of gases. Complete the table. (Carbon dioxide has been done for you.)
Gas Chemical formula % in air
nitrogen 78
oxygen O2
argon 0.9
carbon dioxide CO2 0.03
(3)
(b) The air in the balloon is heated using a propane burner. Propane, C3H8, is a hydrocarbon that burns in air forming carbon dioxide, CO2, and water, H2O.
(i) What does hydrocarbon mean?
______________________________________________________________
______________________________________________________________(1)
(ii) Which gas, in the air, reacts with propane when it burns?
______________________________________________________________(1)
(iii) What type of chemical reaction happens when a hydrocarbon burns?
______________________________________________________________(1)
(iv) The formation of more carbon dioxide causes global problems. Explain why.
______________________________________________________________
______________________________________________________________
______________________________________________________________
Page 40 of 41
______________________________________________________________(2)
(Total 8 marks)
Page 41 of 41