Q1.
Limestone and the products of limestone have many uses.
(a)
Limestone is quarried.
Photograph © Lonny Kalfus / Getty Images
Quarrying limestone has impacts that cause environmental problems.
Tick ( ) two impacts that cause environmental problems.
Impact of quarrying
Tick ( )
Puts off tourists
Causes dust pollution
Increases jobs
Increases traffic
(2)
(b)
Limestone contains calcium carbonate, CaCO3. When it is heated calcium carbonate
produces calcium oxide and carbon dioxide.
The word equation for this reaction is:
calcium carbonate → calcium oxide + carbon dioxide
(i)
Complete the sentence.
The reaction when calcium carbonate is heated is called
thermal ...........................................
(1)
(ii)
100 g of calcium carbonate was heated and produced 56 g of calcium oxide.
Calculate the mass of carbon dioxide produced.
...............................................................................................................
....................................... g
(1)
Page 1 of 15
(c)
The flow chart shows the stages in the limestone cycle.
Complete the names of the calcium compounds formed in the flow chart.
(2)
(Total 6 marks)
Page 2 of 15
Q2.
An old lime kiln made in the ground is shown.
(a)
The thermal decomposition of calcium carbonate makes a white solid and carbon dioxide.
(i)
Name a naturally occurring form of calcium carbonate.
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
What does thermal decomposition mean?
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
Suggest and explain the purpose of the coal.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(iv)
Write a word equation for the thermal decomposition of calcium carbonate.
................................... → ................................... + ....................................
(2)
Page 3 of 15
(b)
The diagrams show what happens when drops of cold water are added to the white solid
formed by heating calcium carbonate.
(ii)
What type of chemical reaction takes place?
...........................................................................................................................
(1)
(ii)
Give the chemical name of the solid formed. Give a use of this solid.
Name ................................................................................................................
Use ...................................................................................................................
(2)
(Total 10 marks)
Q3.
Limestone contains calcium carbonate.
(a)
Calcium carbonate has the formula CaCO3.
Complete the sentence by writing in the correct numbers.
The formula of calcium carbonate is made up of 1 calcium atom, ............ carbon atom(s)
and ............ oxygen atom(s).
(2)
(b)
When limestone is heated it forms two other compounds.
(i)
State one safety precaution that you should take when heating limestone.
...........................................................................................................................
(1)
(ii)
Name the white solid produced.
...........................................................................................................................
(1)
Page 4 of 15
(iii)
Why does a piece of limestone lose mass as it is heated?
...........................................................................................................................
...........................................................................................................................
(1)
(d)
A company wants to quarry limestone. There are some houses near the quarry.
Residents in the houses say that they do not want a quarry next to them.
(i)
Suggest two reasons why they do not want the quarry next to them.
1 ........................................................................................................................
...........................................................................................................................
2 ........................................................................................................................
...........................................................................................................................
(2)
(ii)
Suggest one possible benefit to the residents of having a quarry near their houses.
...........................................................................................................................
...........................................................................................................................
(1)
(Total 8 marks)
Page 5 of 15
Q4.
Limestone is mainly calcium carbonate.
(a)
Quicklime is produced by heating limestone.
(i)
Complete the word equation for this reaction by writing the chemical name of the
solid and the gas produced.
calcium carbonate →
................................. + ................................. .
(2)
(ii)
What is the name for this type of chemical reaction?
..........................................................................................................................
(1)
(b)
Quicklime is used in self-heating cans.
The diagram shows a self-heating can designed to raise the temperature of coffee to
60 °C.
The button on the base of the can is pushed. The foil separator breaks, allowing water to
mix with the quicklime. After about 3 minutes, the can is opened by the ring pull. Insulating
materials are used inside the walls of the can to prevent either the lips or the fingers from
being burned.
(i)
Explain why the coffee becomes hot.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
Page 6 of 15
(ii)
Suggest two reasons why it is not possible to re-use this self-heating can.
1 .......................................................................................................................
..........................................................................................................................
2 .......................................................................................................................
..........................................................................................................................
(2)
(Total 7 marks)
Q5.
Limestone contains calcium carbonate, CaCO3.
At a cement works, limestone is mixed with clay and heated in a kiln.
(a)
(i)
When methane is burned in this process the waste gases contain carbon dioxide
and nitrogen.
Explain why.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Complete the symbol equation for the thermal decomposition of calcium carbonate.
CaCO3 → ......................... + .........................
(2)
Page 7 of 15
(b)
A different fuel is burnt at the cement works.
Suggest one reason the company may give for using this different fuel at the cement
works.
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
The cement works continue to burn the different fuel.
Local residents are concerned because more children are suffering asthma attacks.
Residents have also noticed that parked cars are becoming dirty because of smoke
particles from the chimney.
The table shows the possible medical risk from smoke particles.
Particle size in mm
Medical effect
Larger than 0.4
No medical risks known
0.3 and smaller
Causes asthma attacks
0.2 and smaller
May cause cancer
It is also recommended that to avoid damage to health, the concentration of any particles
should be no higher than 2 parts per million (ppm).
Scientists were brought in to monitor the emissions from the cement work’s chimney.
They positioned four sensors around the cement works to monitor airborne smoke
particles.
These four sensors only detect particle sizes larger than 0.5 mm and measure the
concentration of particles in ppm. The scientists reported that the particle sensors showed
that the average concentration of particles was 1.8 ppm. The scientists concluded that
there was no risk to health.
Page 8 of 15
(i)
Explain why the local residents objected to the positions of the four sensors.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
What evidence did the scientists use to conclude that there was no risk to health?
...........................................................................................................................
...........................................................................................................................
(1)
(iii)
The local residents were still concerned that there was a risk to health, even though
the average concentration of particles was 1.8 ppm.
Explain why.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(Total 11 marks)
Page 9 of 15
M1.
(a)
causes dust pollution
1
increases traffic
1
(b)
(i)
decomposition
1
(ii)
44(g)
1
(c)
(calcium) hydroxide
1
(calcium) carbonate
1
substances must be in the order shown
[6]
M2.
(a)
(i)
limestone / chalk / marble
1
(ii)
breakdown / splits up
1
with heat
1
(iii)
to burn / react with air / oxygen
1
release energy / heat / exothermic / keeps temperature high
1
(iv) calcium carbonate → calcium oxide + carbon dioxide
calcium oxide
1
correct equation
1
(b)
(i)
exothermic / slaking / hydration
not hydrolysis
1
Page 10 of 15
(ii)
calcium hydroxide / slaked line
1
mortar / neutralise acidity in soil / neutralise acid lake water / soften
hard water / to make cement
not in agriculture
not to make lime water
1
[10]
M3.
(a)
1 / one
1
3 / three
1
(b)
(i)
(wear safety) glasses / masks / gloves
accept do not handle hot objects / use
tongs or accept other safety points
such as, ‘tie hair back’
1
(ii)
calcium oxide
accept quicklime
1
(iii)
carbon dioxide / CO2 is given off
accept a gas is given off
1
(d)
(i)
any two from:
•
dust / atmospheric pollution
•
noise
•
eyesore
•
destroys habitats
•
(extra) traffic
•
any other named pollution or description of pollution
2
Page 11 of 15
(ii)
any one from:
•
employment
•
increases local trade / makes money
•
future development of quarry recreation / park / lake / reservoir
do not accept cheaper houses / land /
new roads
1
[8]
M4.
(a)
(i)
calcium oxide / CaO
1
carbon dioxide / CO2
products can be in either order
ignore chemical names other than calcium oxide or carbon dioxide
1
(ii)
(thermal) decomposition
accept endothermic
1
(b)
(i)
(chemical) reaction / react
accept calcium hydroxide / slaked lime produced
ignore incorrect products
1
energy / heat released / exothermic
ignore gets hot / heats up
if neither mark awarded then allow ‘mixing the chemicals heats up
the coffee’ for 1 mark
1
(ii)
any two from:
•
foil has been broken(*)
•
ring pull used(*)
(*)if neither mark awarded accept ‘cannot / difficult to repair’ for 1
mark
ignore button pushed
•
quicklime and / or water mixed / reacted
accept reaction not reversible
accept cannot / difficult to replace quicklime / water / chemicals
2
[7]
Page 12 of 15
M5.
(a)
(i)
oxygen / air reacts with carbon / methane (to form carbon dioxide)
accept from the decomposition / reaction of calcium carbonate
ignore CO2 from the air
1
nitrogen is (unreacted) from the air
1
(ii)
CaO
1
CO2
any order
ignore words
any incorrect balancing max 1 mark
1
(b)
any one from:
•
more energy / efficient
allow converse for present fuel
•
from a sustainable / renewable resource
•
produces less / no carbon dioxide / greenhouse gases / global warming
ignore no pollution / environmental damage
•
more profit or money for local economy
accept fuel is cheap(er)
•
more readily available
it = different fuel
1
(c)
(i)
any two from:
•
not near where people / residents live
accept not between cement works and where people live
ignore sensors are unsightly
•
not positioned where concentration of particles was likely to be highest
•
not positioned downwind
2
(ii)
the average / concentration was 1.8(ppm) or the average / concentration
was below 2(ppm)
accept 1.8(ppm) is less than 2.0 (ppm)
1
Page 13 of 15
(iii)
any three from:
•
children / people suffering asthma attacks
•
result was an average
•
readings (at some (2/3) sensors) could have been higher than 2ppm
•
sensors did not detect particles below 0.5mm
•
small particles / particles below 0.5mm / 0.4mm / 0.3mm / 0.2mm could (still)
cause cancer / asthma
ignore global dimming or cars becoming dirty or position of
sensors
3
[11]
Page 14 of 15
Page 15 of 15