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Transcript of G-Model_Paper_2-IGCSE chem CD.pdf
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 110
1Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
Model exam papers
Paper 2
1 Below is a list o elements Use these elements to answer the questions
below
Each element may be used once more than once or not at all
aluminium
helium
magnesium
potassium
nitrogenoxygen
phosphorus
a Which elements are commonly ound in ertilisers
[3]
b Which two elements are in Period 2 o the Periodic able
and
[2]
c Which elements are gases at room temperature
[2]
d Which element reacts with water to orm an alkali
[1]
e Which two elements have two electrons in their outside orbit
and [2]
otal [10]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 210
2 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
2 Platinum is a rare and valuable metal which is ound in the
ground as a pure metal
itanium is a common metal which is quite expensive because it is
hard to extract
Iron is a common metal which can be extracted rom its ore byheating with carbon
a Using the inormation above place the three metals in order o
reactivity
[1]
b Platinum is an unreactive metal and is used in jewellery
because it doesnrsquot corrode
Give another important use o platinum
[1]
c itanium is an important engineering metal It is stronger
than steel but is only hal as heavy
Suggest why titanium is not used or building motor vehicles
[1]
d
firebrick lining
raw materials
waste gases
air
slag
molten iron
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 310
3Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
Te diagram above shows a blast urnace used or the
extraction rom its ore
i Name the ore rom which iron is extracted
[1]
ii What other raw materials are added at the top o the
urnace besides the ore
and [2]
iii Name two gases which are ound in the waste gases which
come out rom the top o the urnace
and [2]
e Te iron which comes out o the blast urnace (cast iron)
contains carbon which makes it brittle
How is this carbon removed
[2]
f Te result o removing some o the carbon is an alloy called steel
What is the meaning o the term alloy
[1]
g Stainless steel can be made by adding nickel and chromium to
steel Give a use o stainless steel
[1]
otal [12]
3 A student made a soluble salt o the metal zinc by the ollowing
method
A Acid was poured into a beaker
B Zinc was added to the acid until in excess
C Te beaker was warmed and then stirred
D When the reaction was over the remaining zinc was removed
E Te solution was then boiled gently until crystallisation point
F Te remaining solution was lef to cool
a How would the student know that excess zinc had been added
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 410
4 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b In the space below draw and label apparatus suitable to
perorm step D
[3]
c How would the student know that the solution had reached
crystallisation point (step E)
[1]
d A sample o the salt obtained was dissolved in distilled water
and tested by adding barium chloride solution A white
precipitate was ormed
What was the name o the acid that the student used in step A
[1]
e In a second test aqueous ammonia was added to a solution o the
salt 1047297rst slowly and then in excess
What observations were made
[3]
otal [9]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 510
5Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
4 A sample o air was taken in the middle o a city Te air was analysed
and the gases listed below were ound to be present
carbon dioxide
carbon monoxide
methane
nitrogennitrogen dioxide
oxygen
sulfur dioxide
a Which gas would be present in the greatest quantity
[1]
b Which two gases could cause acid rain
and [2]
c Which two gases are most responsible or global warming
and [2]
d Which gas is produced by plants in photosynthesis
[1]
e In the diagram below join each polluting gas to its correct
source [3]
Carbon monoxide
Methane
Sulfur dioxide Cows and sheep
Power stations
Car exhausts
f Argon is always present in the air but it is not in the list above
Suggest why it might not have been detected when the gas was
analysed
[1]
otal [10]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 610
6 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
5
negativeelectrode
carbonrods
concentratedaqueous sodiumchloride andUniversal lndicator
positiveelectrode
+ ndash
Te diagram shows an apparatus which can be used to electrolyse
concentrated sodium chloride solution (brine)
a Chlorine is one o the products o this electrolysis At which
electrode is it ormed
[1]
b At the other electrode the Universal Indicator solution turns
purple What substance causes this change
[1]
c Brine is a mixture o solid sodium chloride and water Brine conducts
electricity but water does not Why doesnrsquot water conduct electricity
[1]
d Sodium chloride is made up o ions Why does it conduct when it
is a solution but not when it is a solid
[1]
e Te electrodes are made rom graphite a orm o carbon
Graphite has a giant covalent structure What unusual
property does it have that allows it to be used as an electrode
[1]
f Diamond is another orm o carbon with a different type o giant
covalent structure
By comparing their structures explain why diamond but not
graphite can be used in cutting
[2]
otal [7]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 710
7Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
6 A student wished to make a sample o ertiliser by reacting ammonia
solution with nitric acid
20 cm3 o ammonia was placed in a 1047298ask and Universal Indicator
was added Nitric acid was added 2 cm3 at a time using a measuring
cylinder and the pH o the solution was noted afer each addition Te
results are shown in the table below
a Plot the pH values on the grid below
Join the points to each other using straight lines [4]
p H
0 2 4 6
Volume of acid added cm3
8 10 12 14 16 18 20
Volumeadded cm3
0 2 4 6 8 10 12 14 16 18 20
pH 13 13 13 12 12 9 3 2 2 1 1
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 810
8 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b Use your graph to estimate how much acid was needed to exactly
neutralise the ammonia
[2]
c Te equation or the reaction is NH3 + HNO3 rarr NH4NO3
Rewrite this equation as a word equation
[2]
d Why is this ertiliser a particularly good one
[1]
otal [9]
7 Te diagram shows a ractionating column used or separating
petroleum into useul ractions
fractionsfuel gas
petrol
paraffin
light gas oil
diesel
lubricating fraction
bitumen
crude oil
a Draw a lsquotimesrsquo on the diagram at the point where the temperature is
highest [1]
b Paraffi n is ofen called kerosene What is its major use
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 910
9Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
c Te uel gas (re1047297nery gas) raction contains compounds which are gases
at room temperature Tese gases are ofen cracked to orm alkenes
What is meant by the terms cracking and alkene
Cracking [1]
Alkene [1]
d Butane C4H10 can be cracked to orm two molecules o ethene C2H4
Complete the equation below by identiying the other product
C4H10 rarr 2C2H4 + [1]
e Ethene can be converted into ethanol by reacting it with steam
Write a word equation or this reaction
[2]
f In the space below draw the structure o the ethanol molecule
showing all atoms and bonds
[2]
g State another method o making ethanol and give a use or the
compound
Method
Use [2]
otal [11]
8 a Complete the table below by 1047297lling in the empty spaces
Symbol Number ofprotons
Number ofneutrons
Number ofelectrons
H 1 1 1
8 8 8
O2minus 8 8
C 6 6
1 0 1
[4]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 1010
10 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b What is the meaning o the term isotope
[1]
c Using an example rom the table above give an example o
isotopes
[2]
d 235U is an example o an isotope used to produce energy
How is it used
[1]
e Hydrogen is also used as a uel Write a word equation to showwhat happens when hydrogen burns
[2]
f Hydrogen was once used in airships but now helium is used
instead
Why is helium a suitable gas or use in airships
[2]
otal [12]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 210
2 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
2 Platinum is a rare and valuable metal which is ound in the
ground as a pure metal
itanium is a common metal which is quite expensive because it is
hard to extract
Iron is a common metal which can be extracted rom its ore byheating with carbon
a Using the inormation above place the three metals in order o
reactivity
[1]
b Platinum is an unreactive metal and is used in jewellery
because it doesnrsquot corrode
Give another important use o platinum
[1]
c itanium is an important engineering metal It is stronger
than steel but is only hal as heavy
Suggest why titanium is not used or building motor vehicles
[1]
d
firebrick lining
raw materials
waste gases
air
slag
molten iron
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 310
3Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
Te diagram above shows a blast urnace used or the
extraction rom its ore
i Name the ore rom which iron is extracted
[1]
ii What other raw materials are added at the top o the
urnace besides the ore
and [2]
iii Name two gases which are ound in the waste gases which
come out rom the top o the urnace
and [2]
e Te iron which comes out o the blast urnace (cast iron)
contains carbon which makes it brittle
How is this carbon removed
[2]
f Te result o removing some o the carbon is an alloy called steel
What is the meaning o the term alloy
[1]
g Stainless steel can be made by adding nickel and chromium to
steel Give a use o stainless steel
[1]
otal [12]
3 A student made a soluble salt o the metal zinc by the ollowing
method
A Acid was poured into a beaker
B Zinc was added to the acid until in excess
C Te beaker was warmed and then stirred
D When the reaction was over the remaining zinc was removed
E Te solution was then boiled gently until crystallisation point
F Te remaining solution was lef to cool
a How would the student know that excess zinc had been added
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 410
4 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b In the space below draw and label apparatus suitable to
perorm step D
[3]
c How would the student know that the solution had reached
crystallisation point (step E)
[1]
d A sample o the salt obtained was dissolved in distilled water
and tested by adding barium chloride solution A white
precipitate was ormed
What was the name o the acid that the student used in step A
[1]
e In a second test aqueous ammonia was added to a solution o the
salt 1047297rst slowly and then in excess
What observations were made
[3]
otal [9]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 510
5Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
4 A sample o air was taken in the middle o a city Te air was analysed
and the gases listed below were ound to be present
carbon dioxide
carbon monoxide
methane
nitrogennitrogen dioxide
oxygen
sulfur dioxide
a Which gas would be present in the greatest quantity
[1]
b Which two gases could cause acid rain
and [2]
c Which two gases are most responsible or global warming
and [2]
d Which gas is produced by plants in photosynthesis
[1]
e In the diagram below join each polluting gas to its correct
source [3]
Carbon monoxide
Methane
Sulfur dioxide Cows and sheep
Power stations
Car exhausts
f Argon is always present in the air but it is not in the list above
Suggest why it might not have been detected when the gas was
analysed
[1]
otal [10]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 610
6 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
5
negativeelectrode
carbonrods
concentratedaqueous sodiumchloride andUniversal lndicator
positiveelectrode
+ ndash
Te diagram shows an apparatus which can be used to electrolyse
concentrated sodium chloride solution (brine)
a Chlorine is one o the products o this electrolysis At which
electrode is it ormed
[1]
b At the other electrode the Universal Indicator solution turns
purple What substance causes this change
[1]
c Brine is a mixture o solid sodium chloride and water Brine conducts
electricity but water does not Why doesnrsquot water conduct electricity
[1]
d Sodium chloride is made up o ions Why does it conduct when it
is a solution but not when it is a solid
[1]
e Te electrodes are made rom graphite a orm o carbon
Graphite has a giant covalent structure What unusual
property does it have that allows it to be used as an electrode
[1]
f Diamond is another orm o carbon with a different type o giant
covalent structure
By comparing their structures explain why diamond but not
graphite can be used in cutting
[2]
otal [7]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 710
7Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
6 A student wished to make a sample o ertiliser by reacting ammonia
solution with nitric acid
20 cm3 o ammonia was placed in a 1047298ask and Universal Indicator
was added Nitric acid was added 2 cm3 at a time using a measuring
cylinder and the pH o the solution was noted afer each addition Te
results are shown in the table below
a Plot the pH values on the grid below
Join the points to each other using straight lines [4]
p H
0 2 4 6
Volume of acid added cm3
8 10 12 14 16 18 20
Volumeadded cm3
0 2 4 6 8 10 12 14 16 18 20
pH 13 13 13 12 12 9 3 2 2 1 1
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 810
8 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b Use your graph to estimate how much acid was needed to exactly
neutralise the ammonia
[2]
c Te equation or the reaction is NH3 + HNO3 rarr NH4NO3
Rewrite this equation as a word equation
[2]
d Why is this ertiliser a particularly good one
[1]
otal [9]
7 Te diagram shows a ractionating column used or separating
petroleum into useul ractions
fractionsfuel gas
petrol
paraffin
light gas oil
diesel
lubricating fraction
bitumen
crude oil
a Draw a lsquotimesrsquo on the diagram at the point where the temperature is
highest [1]
b Paraffi n is ofen called kerosene What is its major use
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 910
9Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
c Te uel gas (re1047297nery gas) raction contains compounds which are gases
at room temperature Tese gases are ofen cracked to orm alkenes
What is meant by the terms cracking and alkene
Cracking [1]
Alkene [1]
d Butane C4H10 can be cracked to orm two molecules o ethene C2H4
Complete the equation below by identiying the other product
C4H10 rarr 2C2H4 + [1]
e Ethene can be converted into ethanol by reacting it with steam
Write a word equation or this reaction
[2]
f In the space below draw the structure o the ethanol molecule
showing all atoms and bonds
[2]
g State another method o making ethanol and give a use or the
compound
Method
Use [2]
otal [11]
8 a Complete the table below by 1047297lling in the empty spaces
Symbol Number ofprotons
Number ofneutrons
Number ofelectrons
H 1 1 1
8 8 8
O2minus 8 8
C 6 6
1 0 1
[4]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 1010
10 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b What is the meaning o the term isotope
[1]
c Using an example rom the table above give an example o
isotopes
[2]
d 235U is an example o an isotope used to produce energy
How is it used
[1]
e Hydrogen is also used as a uel Write a word equation to showwhat happens when hydrogen burns
[2]
f Hydrogen was once used in airships but now helium is used
instead
Why is helium a suitable gas or use in airships
[2]
otal [12]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 310
3Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
Te diagram above shows a blast urnace used or the
extraction rom its ore
i Name the ore rom which iron is extracted
[1]
ii What other raw materials are added at the top o the
urnace besides the ore
and [2]
iii Name two gases which are ound in the waste gases which
come out rom the top o the urnace
and [2]
e Te iron which comes out o the blast urnace (cast iron)
contains carbon which makes it brittle
How is this carbon removed
[2]
f Te result o removing some o the carbon is an alloy called steel
What is the meaning o the term alloy
[1]
g Stainless steel can be made by adding nickel and chromium to
steel Give a use o stainless steel
[1]
otal [12]
3 A student made a soluble salt o the metal zinc by the ollowing
method
A Acid was poured into a beaker
B Zinc was added to the acid until in excess
C Te beaker was warmed and then stirred
D When the reaction was over the remaining zinc was removed
E Te solution was then boiled gently until crystallisation point
F Te remaining solution was lef to cool
a How would the student know that excess zinc had been added
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 410
4 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b In the space below draw and label apparatus suitable to
perorm step D
[3]
c How would the student know that the solution had reached
crystallisation point (step E)
[1]
d A sample o the salt obtained was dissolved in distilled water
and tested by adding barium chloride solution A white
precipitate was ormed
What was the name o the acid that the student used in step A
[1]
e In a second test aqueous ammonia was added to a solution o the
salt 1047297rst slowly and then in excess
What observations were made
[3]
otal [9]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 510
5Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
4 A sample o air was taken in the middle o a city Te air was analysed
and the gases listed below were ound to be present
carbon dioxide
carbon monoxide
methane
nitrogennitrogen dioxide
oxygen
sulfur dioxide
a Which gas would be present in the greatest quantity
[1]
b Which two gases could cause acid rain
and [2]
c Which two gases are most responsible or global warming
and [2]
d Which gas is produced by plants in photosynthesis
[1]
e In the diagram below join each polluting gas to its correct
source [3]
Carbon monoxide
Methane
Sulfur dioxide Cows and sheep
Power stations
Car exhausts
f Argon is always present in the air but it is not in the list above
Suggest why it might not have been detected when the gas was
analysed
[1]
otal [10]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 610
6 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
5
negativeelectrode
carbonrods
concentratedaqueous sodiumchloride andUniversal lndicator
positiveelectrode
+ ndash
Te diagram shows an apparatus which can be used to electrolyse
concentrated sodium chloride solution (brine)
a Chlorine is one o the products o this electrolysis At which
electrode is it ormed
[1]
b At the other electrode the Universal Indicator solution turns
purple What substance causes this change
[1]
c Brine is a mixture o solid sodium chloride and water Brine conducts
electricity but water does not Why doesnrsquot water conduct electricity
[1]
d Sodium chloride is made up o ions Why does it conduct when it
is a solution but not when it is a solid
[1]
e Te electrodes are made rom graphite a orm o carbon
Graphite has a giant covalent structure What unusual
property does it have that allows it to be used as an electrode
[1]
f Diamond is another orm o carbon with a different type o giant
covalent structure
By comparing their structures explain why diamond but not
graphite can be used in cutting
[2]
otal [7]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 710
7Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
6 A student wished to make a sample o ertiliser by reacting ammonia
solution with nitric acid
20 cm3 o ammonia was placed in a 1047298ask and Universal Indicator
was added Nitric acid was added 2 cm3 at a time using a measuring
cylinder and the pH o the solution was noted afer each addition Te
results are shown in the table below
a Plot the pH values on the grid below
Join the points to each other using straight lines [4]
p H
0 2 4 6
Volume of acid added cm3
8 10 12 14 16 18 20
Volumeadded cm3
0 2 4 6 8 10 12 14 16 18 20
pH 13 13 13 12 12 9 3 2 2 1 1
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 810
8 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b Use your graph to estimate how much acid was needed to exactly
neutralise the ammonia
[2]
c Te equation or the reaction is NH3 + HNO3 rarr NH4NO3
Rewrite this equation as a word equation
[2]
d Why is this ertiliser a particularly good one
[1]
otal [9]
7 Te diagram shows a ractionating column used or separating
petroleum into useul ractions
fractionsfuel gas
petrol
paraffin
light gas oil
diesel
lubricating fraction
bitumen
crude oil
a Draw a lsquotimesrsquo on the diagram at the point where the temperature is
highest [1]
b Paraffi n is ofen called kerosene What is its major use
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 910
9Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
c Te uel gas (re1047297nery gas) raction contains compounds which are gases
at room temperature Tese gases are ofen cracked to orm alkenes
What is meant by the terms cracking and alkene
Cracking [1]
Alkene [1]
d Butane C4H10 can be cracked to orm two molecules o ethene C2H4
Complete the equation below by identiying the other product
C4H10 rarr 2C2H4 + [1]
e Ethene can be converted into ethanol by reacting it with steam
Write a word equation or this reaction
[2]
f In the space below draw the structure o the ethanol molecule
showing all atoms and bonds
[2]
g State another method o making ethanol and give a use or the
compound
Method
Use [2]
otal [11]
8 a Complete the table below by 1047297lling in the empty spaces
Symbol Number ofprotons
Number ofneutrons
Number ofelectrons
H 1 1 1
8 8 8
O2minus 8 8
C 6 6
1 0 1
[4]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 1010
10 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b What is the meaning o the term isotope
[1]
c Using an example rom the table above give an example o
isotopes
[2]
d 235U is an example o an isotope used to produce energy
How is it used
[1]
e Hydrogen is also used as a uel Write a word equation to showwhat happens when hydrogen burns
[2]
f Hydrogen was once used in airships but now helium is used
instead
Why is helium a suitable gas or use in airships
[2]
otal [12]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 410
4 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b In the space below draw and label apparatus suitable to
perorm step D
[3]
c How would the student know that the solution had reached
crystallisation point (step E)
[1]
d A sample o the salt obtained was dissolved in distilled water
and tested by adding barium chloride solution A white
precipitate was ormed
What was the name o the acid that the student used in step A
[1]
e In a second test aqueous ammonia was added to a solution o the
salt 1047297rst slowly and then in excess
What observations were made
[3]
otal [9]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 510
5Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
4 A sample o air was taken in the middle o a city Te air was analysed
and the gases listed below were ound to be present
carbon dioxide
carbon monoxide
methane
nitrogennitrogen dioxide
oxygen
sulfur dioxide
a Which gas would be present in the greatest quantity
[1]
b Which two gases could cause acid rain
and [2]
c Which two gases are most responsible or global warming
and [2]
d Which gas is produced by plants in photosynthesis
[1]
e In the diagram below join each polluting gas to its correct
source [3]
Carbon monoxide
Methane
Sulfur dioxide Cows and sheep
Power stations
Car exhausts
f Argon is always present in the air but it is not in the list above
Suggest why it might not have been detected when the gas was
analysed
[1]
otal [10]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 610
6 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
5
negativeelectrode
carbonrods
concentratedaqueous sodiumchloride andUniversal lndicator
positiveelectrode
+ ndash
Te diagram shows an apparatus which can be used to electrolyse
concentrated sodium chloride solution (brine)
a Chlorine is one o the products o this electrolysis At which
electrode is it ormed
[1]
b At the other electrode the Universal Indicator solution turns
purple What substance causes this change
[1]
c Brine is a mixture o solid sodium chloride and water Brine conducts
electricity but water does not Why doesnrsquot water conduct electricity
[1]
d Sodium chloride is made up o ions Why does it conduct when it
is a solution but not when it is a solid
[1]
e Te electrodes are made rom graphite a orm o carbon
Graphite has a giant covalent structure What unusual
property does it have that allows it to be used as an electrode
[1]
f Diamond is another orm o carbon with a different type o giant
covalent structure
By comparing their structures explain why diamond but not
graphite can be used in cutting
[2]
otal [7]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 710
7Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
6 A student wished to make a sample o ertiliser by reacting ammonia
solution with nitric acid
20 cm3 o ammonia was placed in a 1047298ask and Universal Indicator
was added Nitric acid was added 2 cm3 at a time using a measuring
cylinder and the pH o the solution was noted afer each addition Te
results are shown in the table below
a Plot the pH values on the grid below
Join the points to each other using straight lines [4]
p H
0 2 4 6
Volume of acid added cm3
8 10 12 14 16 18 20
Volumeadded cm3
0 2 4 6 8 10 12 14 16 18 20
pH 13 13 13 12 12 9 3 2 2 1 1
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 810
8 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b Use your graph to estimate how much acid was needed to exactly
neutralise the ammonia
[2]
c Te equation or the reaction is NH3 + HNO3 rarr NH4NO3
Rewrite this equation as a word equation
[2]
d Why is this ertiliser a particularly good one
[1]
otal [9]
7 Te diagram shows a ractionating column used or separating
petroleum into useul ractions
fractionsfuel gas
petrol
paraffin
light gas oil
diesel
lubricating fraction
bitumen
crude oil
a Draw a lsquotimesrsquo on the diagram at the point where the temperature is
highest [1]
b Paraffi n is ofen called kerosene What is its major use
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 910
9Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
c Te uel gas (re1047297nery gas) raction contains compounds which are gases
at room temperature Tese gases are ofen cracked to orm alkenes
What is meant by the terms cracking and alkene
Cracking [1]
Alkene [1]
d Butane C4H10 can be cracked to orm two molecules o ethene C2H4
Complete the equation below by identiying the other product
C4H10 rarr 2C2H4 + [1]
e Ethene can be converted into ethanol by reacting it with steam
Write a word equation or this reaction
[2]
f In the space below draw the structure o the ethanol molecule
showing all atoms and bonds
[2]
g State another method o making ethanol and give a use or the
compound
Method
Use [2]
otal [11]
8 a Complete the table below by 1047297lling in the empty spaces
Symbol Number ofprotons
Number ofneutrons
Number ofelectrons
H 1 1 1
8 8 8
O2minus 8 8
C 6 6
1 0 1
[4]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 1010
10 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b What is the meaning o the term isotope
[1]
c Using an example rom the table above give an example o
isotopes
[2]
d 235U is an example o an isotope used to produce energy
How is it used
[1]
e Hydrogen is also used as a uel Write a word equation to showwhat happens when hydrogen burns
[2]
f Hydrogen was once used in airships but now helium is used
instead
Why is helium a suitable gas or use in airships
[2]
otal [12]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 510
5Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
4 A sample o air was taken in the middle o a city Te air was analysed
and the gases listed below were ound to be present
carbon dioxide
carbon monoxide
methane
nitrogennitrogen dioxide
oxygen
sulfur dioxide
a Which gas would be present in the greatest quantity
[1]
b Which two gases could cause acid rain
and [2]
c Which two gases are most responsible or global warming
and [2]
d Which gas is produced by plants in photosynthesis
[1]
e In the diagram below join each polluting gas to its correct
source [3]
Carbon monoxide
Methane
Sulfur dioxide Cows and sheep
Power stations
Car exhausts
f Argon is always present in the air but it is not in the list above
Suggest why it might not have been detected when the gas was
analysed
[1]
otal [10]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 610
6 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
5
negativeelectrode
carbonrods
concentratedaqueous sodiumchloride andUniversal lndicator
positiveelectrode
+ ndash
Te diagram shows an apparatus which can be used to electrolyse
concentrated sodium chloride solution (brine)
a Chlorine is one o the products o this electrolysis At which
electrode is it ormed
[1]
b At the other electrode the Universal Indicator solution turns
purple What substance causes this change
[1]
c Brine is a mixture o solid sodium chloride and water Brine conducts
electricity but water does not Why doesnrsquot water conduct electricity
[1]
d Sodium chloride is made up o ions Why does it conduct when it
is a solution but not when it is a solid
[1]
e Te electrodes are made rom graphite a orm o carbon
Graphite has a giant covalent structure What unusual
property does it have that allows it to be used as an electrode
[1]
f Diamond is another orm o carbon with a different type o giant
covalent structure
By comparing their structures explain why diamond but not
graphite can be used in cutting
[2]
otal [7]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 710
7Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
6 A student wished to make a sample o ertiliser by reacting ammonia
solution with nitric acid
20 cm3 o ammonia was placed in a 1047298ask and Universal Indicator
was added Nitric acid was added 2 cm3 at a time using a measuring
cylinder and the pH o the solution was noted afer each addition Te
results are shown in the table below
a Plot the pH values on the grid below
Join the points to each other using straight lines [4]
p H
0 2 4 6
Volume of acid added cm3
8 10 12 14 16 18 20
Volumeadded cm3
0 2 4 6 8 10 12 14 16 18 20
pH 13 13 13 12 12 9 3 2 2 1 1
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 810
8 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b Use your graph to estimate how much acid was needed to exactly
neutralise the ammonia
[2]
c Te equation or the reaction is NH3 + HNO3 rarr NH4NO3
Rewrite this equation as a word equation
[2]
d Why is this ertiliser a particularly good one
[1]
otal [9]
7 Te diagram shows a ractionating column used or separating
petroleum into useul ractions
fractionsfuel gas
petrol
paraffin
light gas oil
diesel
lubricating fraction
bitumen
crude oil
a Draw a lsquotimesrsquo on the diagram at the point where the temperature is
highest [1]
b Paraffi n is ofen called kerosene What is its major use
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 910
9Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
c Te uel gas (re1047297nery gas) raction contains compounds which are gases
at room temperature Tese gases are ofen cracked to orm alkenes
What is meant by the terms cracking and alkene
Cracking [1]
Alkene [1]
d Butane C4H10 can be cracked to orm two molecules o ethene C2H4
Complete the equation below by identiying the other product
C4H10 rarr 2C2H4 + [1]
e Ethene can be converted into ethanol by reacting it with steam
Write a word equation or this reaction
[2]
f In the space below draw the structure o the ethanol molecule
showing all atoms and bonds
[2]
g State another method o making ethanol and give a use or the
compound
Method
Use [2]
otal [11]
8 a Complete the table below by 1047297lling in the empty spaces
Symbol Number ofprotons
Number ofneutrons
Number ofelectrons
H 1 1 1
8 8 8
O2minus 8 8
C 6 6
1 0 1
[4]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 1010
10 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b What is the meaning o the term isotope
[1]
c Using an example rom the table above give an example o
isotopes
[2]
d 235U is an example o an isotope used to produce energy
How is it used
[1]
e Hydrogen is also used as a uel Write a word equation to showwhat happens when hydrogen burns
[2]
f Hydrogen was once used in airships but now helium is used
instead
Why is helium a suitable gas or use in airships
[2]
otal [12]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 610
6 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
5
negativeelectrode
carbonrods
concentratedaqueous sodiumchloride andUniversal lndicator
positiveelectrode
+ ndash
Te diagram shows an apparatus which can be used to electrolyse
concentrated sodium chloride solution (brine)
a Chlorine is one o the products o this electrolysis At which
electrode is it ormed
[1]
b At the other electrode the Universal Indicator solution turns
purple What substance causes this change
[1]
c Brine is a mixture o solid sodium chloride and water Brine conducts
electricity but water does not Why doesnrsquot water conduct electricity
[1]
d Sodium chloride is made up o ions Why does it conduct when it
is a solution but not when it is a solid
[1]
e Te electrodes are made rom graphite a orm o carbon
Graphite has a giant covalent structure What unusual
property does it have that allows it to be used as an electrode
[1]
f Diamond is another orm o carbon with a different type o giant
covalent structure
By comparing their structures explain why diamond but not
graphite can be used in cutting
[2]
otal [7]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 710
7Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
6 A student wished to make a sample o ertiliser by reacting ammonia
solution with nitric acid
20 cm3 o ammonia was placed in a 1047298ask and Universal Indicator
was added Nitric acid was added 2 cm3 at a time using a measuring
cylinder and the pH o the solution was noted afer each addition Te
results are shown in the table below
a Plot the pH values on the grid below
Join the points to each other using straight lines [4]
p H
0 2 4 6
Volume of acid added cm3
8 10 12 14 16 18 20
Volumeadded cm3
0 2 4 6 8 10 12 14 16 18 20
pH 13 13 13 12 12 9 3 2 2 1 1
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 810
8 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b Use your graph to estimate how much acid was needed to exactly
neutralise the ammonia
[2]
c Te equation or the reaction is NH3 + HNO3 rarr NH4NO3
Rewrite this equation as a word equation
[2]
d Why is this ertiliser a particularly good one
[1]
otal [9]
7 Te diagram shows a ractionating column used or separating
petroleum into useul ractions
fractionsfuel gas
petrol
paraffin
light gas oil
diesel
lubricating fraction
bitumen
crude oil
a Draw a lsquotimesrsquo on the diagram at the point where the temperature is
highest [1]
b Paraffi n is ofen called kerosene What is its major use
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 910
9Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
c Te uel gas (re1047297nery gas) raction contains compounds which are gases
at room temperature Tese gases are ofen cracked to orm alkenes
What is meant by the terms cracking and alkene
Cracking [1]
Alkene [1]
d Butane C4H10 can be cracked to orm two molecules o ethene C2H4
Complete the equation below by identiying the other product
C4H10 rarr 2C2H4 + [1]
e Ethene can be converted into ethanol by reacting it with steam
Write a word equation or this reaction
[2]
f In the space below draw the structure o the ethanol molecule
showing all atoms and bonds
[2]
g State another method o making ethanol and give a use or the
compound
Method
Use [2]
otal [11]
8 a Complete the table below by 1047297lling in the empty spaces
Symbol Number ofprotons
Number ofneutrons
Number ofelectrons
H 1 1 1
8 8 8
O2minus 8 8
C 6 6
1 0 1
[4]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 1010
10 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b What is the meaning o the term isotope
[1]
c Using an example rom the table above give an example o
isotopes
[2]
d 235U is an example o an isotope used to produce energy
How is it used
[1]
e Hydrogen is also used as a uel Write a word equation to showwhat happens when hydrogen burns
[2]
f Hydrogen was once used in airships but now helium is used
instead
Why is helium a suitable gas or use in airships
[2]
otal [12]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 710
7Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
6 A student wished to make a sample o ertiliser by reacting ammonia
solution with nitric acid
20 cm3 o ammonia was placed in a 1047298ask and Universal Indicator
was added Nitric acid was added 2 cm3 at a time using a measuring
cylinder and the pH o the solution was noted afer each addition Te
results are shown in the table below
a Plot the pH values on the grid below
Join the points to each other using straight lines [4]
p H
0 2 4 6
Volume of acid added cm3
8 10 12 14 16 18 20
Volumeadded cm3
0 2 4 6 8 10 12 14 16 18 20
pH 13 13 13 12 12 9 3 2 2 1 1
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 810
8 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b Use your graph to estimate how much acid was needed to exactly
neutralise the ammonia
[2]
c Te equation or the reaction is NH3 + HNO3 rarr NH4NO3
Rewrite this equation as a word equation
[2]
d Why is this ertiliser a particularly good one
[1]
otal [9]
7 Te diagram shows a ractionating column used or separating
petroleum into useul ractions
fractionsfuel gas
petrol
paraffin
light gas oil
diesel
lubricating fraction
bitumen
crude oil
a Draw a lsquotimesrsquo on the diagram at the point where the temperature is
highest [1]
b Paraffi n is ofen called kerosene What is its major use
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 910
9Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
c Te uel gas (re1047297nery gas) raction contains compounds which are gases
at room temperature Tese gases are ofen cracked to orm alkenes
What is meant by the terms cracking and alkene
Cracking [1]
Alkene [1]
d Butane C4H10 can be cracked to orm two molecules o ethene C2H4
Complete the equation below by identiying the other product
C4H10 rarr 2C2H4 + [1]
e Ethene can be converted into ethanol by reacting it with steam
Write a word equation or this reaction
[2]
f In the space below draw the structure o the ethanol molecule
showing all atoms and bonds
[2]
g State another method o making ethanol and give a use or the
compound
Method
Use [2]
otal [11]
8 a Complete the table below by 1047297lling in the empty spaces
Symbol Number ofprotons
Number ofneutrons
Number ofelectrons
H 1 1 1
8 8 8
O2minus 8 8
C 6 6
1 0 1
[4]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 1010
10 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b What is the meaning o the term isotope
[1]
c Using an example rom the table above give an example o
isotopes
[2]
d 235U is an example o an isotope used to produce energy
How is it used
[1]
e Hydrogen is also used as a uel Write a word equation to showwhat happens when hydrogen burns
[2]
f Hydrogen was once used in airships but now helium is used
instead
Why is helium a suitable gas or use in airships
[2]
otal [12]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 810
8 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b Use your graph to estimate how much acid was needed to exactly
neutralise the ammonia
[2]
c Te equation or the reaction is NH3 + HNO3 rarr NH4NO3
Rewrite this equation as a word equation
[2]
d Why is this ertiliser a particularly good one
[1]
otal [9]
7 Te diagram shows a ractionating column used or separating
petroleum into useul ractions
fractionsfuel gas
petrol
paraffin
light gas oil
diesel
lubricating fraction
bitumen
crude oil
a Draw a lsquotimesrsquo on the diagram at the point where the temperature is
highest [1]
b Paraffi n is ofen called kerosene What is its major use
[1]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 910
9Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
c Te uel gas (re1047297nery gas) raction contains compounds which are gases
at room temperature Tese gases are ofen cracked to orm alkenes
What is meant by the terms cracking and alkene
Cracking [1]
Alkene [1]
d Butane C4H10 can be cracked to orm two molecules o ethene C2H4
Complete the equation below by identiying the other product
C4H10 rarr 2C2H4 + [1]
e Ethene can be converted into ethanol by reacting it with steam
Write a word equation or this reaction
[2]
f In the space below draw the structure o the ethanol molecule
showing all atoms and bonds
[2]
g State another method o making ethanol and give a use or the
compound
Method
Use [2]
otal [11]
8 a Complete the table below by 1047297lling in the empty spaces
Symbol Number ofprotons
Number ofneutrons
Number ofelectrons
H 1 1 1
8 8 8
O2minus 8 8
C 6 6
1 0 1
[4]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 1010
10 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b What is the meaning o the term isotope
[1]
c Using an example rom the table above give an example o
isotopes
[2]
d 235U is an example o an isotope used to produce energy
How is it used
[1]
e Hydrogen is also used as a uel Write a word equation to showwhat happens when hydrogen burns
[2]
f Hydrogen was once used in airships but now helium is used
instead
Why is helium a suitable gas or use in airships
[2]
otal [12]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 910
9Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
c Te uel gas (re1047297nery gas) raction contains compounds which are gases
at room temperature Tese gases are ofen cracked to orm alkenes
What is meant by the terms cracking and alkene
Cracking [1]
Alkene [1]
d Butane C4H10 can be cracked to orm two molecules o ethene C2H4
Complete the equation below by identiying the other product
C4H10 rarr 2C2H4 + [1]
e Ethene can be converted into ethanol by reacting it with steam
Write a word equation or this reaction
[2]
f In the space below draw the structure o the ethanol molecule
showing all atoms and bonds
[2]
g State another method o making ethanol and give a use or the
compound
Method
Use [2]
otal [11]
8 a Complete the table below by 1047297lling in the empty spaces
Symbol Number ofprotons
Number ofneutrons
Number ofelectrons
H 1 1 1
8 8 8
O2minus 8 8
C 6 6
1 0 1
[4]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 1010
10 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b What is the meaning o the term isotope
[1]
c Using an example rom the table above give an example o
isotopes
[2]
d 235U is an example o an isotope used to produce energy
How is it used
[1]
e Hydrogen is also used as a uel Write a word equation to showwhat happens when hydrogen burns
[2]
f Hydrogen was once used in airships but now helium is used
instead
Why is helium a suitable gas or use in airships
[2]
otal [12]
8142019 G-Model_Paper_2-IGCSE chem CDpdf
httpslidepdfcomreaderfullg-modelpaper2-igcse-chem-cdpdf 1010
10 Model exam papers ndash Paper 2copy Cambridge University Press IGCSE Chemistry
b What is the meaning o the term isotope
[1]
c Using an example rom the table above give an example o
isotopes
[2]
d 235U is an example o an isotope used to produce energy
How is it used
[1]
e Hydrogen is also used as a uel Write a word equation to showwhat happens when hydrogen burns
[2]
f Hydrogen was once used in airships but now helium is used
instead
Why is helium a suitable gas or use in airships
[2]
otal [12]