Q1.
A student reacted copper carbonate with sulfuric acid.
(a)
Carbon dioxide was produced.
Name the other two products of the reaction between copper carbonate and sulfuric
acid.
1 _________________________________________________________________
2 _________________________________________________________________
(2)
The student measured the volume of carbon dioxide produced.
The volume was recorded every 20 seconds for 180 seconds.
The table shows some of the results.
(b)
Time in seconds
Volume of carbon
dioxide in cm3
0
0
20
16
40
30
60
42
80
53
100
62
120
68
The student observed that the reaction had finished after 160 seconds.
Suggest what the student observed to show that the reaction had finished.
___________________________________________________________________
___________________________________________________________________
(1)
(c)
Complete the graph below.
You should:
•
•
plot the data from the table above on the grid
draw a line of best fit.
The first 2 points from the table have been plotted for you.
Page 1 of 14
(3)
(d)
The concentration of sulfuric acid decreases during the reaction.
Explain how the decreasing concentration of sulfuric acid affects the rate of the
reaction.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(Total 8 marks)
Q2.
Ammonium sulfate is an artificial fertiliser.
Page 2 of 14
(a)
A student tested this fertiliser to prove that it contained ammonium ions and sulfate
ions.
Draw a ring around the correct answer to complete each sentence.
(i)
Test for ammonium ions (NH4+).
sodium chloride solution
The student added
sodium hydroxide solution
to the fertiliser.
dilute sulfuric acid
A gas called ammonia was produced.
blue.
Ammonia turns damp litmus paper
green.
red.
(2)
(ii)
Test for sulfate ions (SO42–).
barium chloride
The student added
silver nitrate
solution to a solution of the fertiliser.
sodium chloride
blue
A
red
precipitate was formed.
white
(2)
Page 3 of 14
(b)
Ammonium sulfate is made by reacting sulfuric acid with ammonia solution.
Sulfuric acid is a strong acid.
Draw a ring around the correct answer to complete the sentence.
difficult to break.
The word strong means that the acid is
very concentrated.
fully ionised in water.
(1)
(c)
Use the information about acids in the table to help you answer these questions.
Name of chemical
Ions produced in
aqueous solution
pH
Universal Indicator
added
Ethanoic acid
H+
CH3COO–
5
Goes orange
Sulfuric acid
H+
SO42–
1
Goes red
Draw a ring around the correct answer to complete each sentence.
(i)
Sulfuric acid and ethanoic acid are both acids because
CH3COO– ions.
they contain
H+ ions.
SO42– ions.
(1)
(ii)
Sulfuric acid is a stronger acid than ethanoic acid.
higher than
The pH of stronger acids is
lower than
the pH of weaker acids.
the same as
(1)
(d)
The volume of sulfuric acid that reacts with 25.0 cm3 of ammonia solution can be
found by titration.
The diagram shows the apparatus used for the titration.
Page 4 of 14
A student did the titration five times and recorded the following results.
Titration
Volume of acid added in cm3
(i)
1
2
3
4
5
13.3
13.9
13.2
13.1
13.2
How did the student know when enough sulfuric acid had been added to
neutralise the ammonia solution?
______________________________________________________________
______________________________________________________________
(1)
(ii)
The student did not use one of the results because it was anomalous.
Which result was anomalous? ______________________________________
(1)
(iii)
Use the other four results to calculate the mean volume of sulfuric acid that
reacted with the ammonia.
______________________________________________________________
______________________________________________________________
Mean volume = ____________________ cm3
(1)
(Total 10 marks)
Q3.
This question is about acids and salts.
(a)
Nitric acid can be used to produce salts.
Page 5 of 14
What is the formula of nitric acid?
Tick (✓) one box.
CH3COOH
HNO3
H2SO4
(1)
(b)
What is the symbol of the ion that makes solutions acidic?
_______________
(1)
(c)
Name the salt produced when hydrochloric acid reacts with zinc oxide.
___________________________________________________________________
(1)
(d)
Phosphoric acid (H3PO4) reacts with magnesium carbonate to produce a salt.
Complete the equation for the reaction.
You should balance the equation.
2 H3PO4 +
______
MgCO3 ⟶ Mg3(PO4)2 +
_______
+
_______
(2)
(e)
Plan a method to produce pure, dry crystals of copper sulfate from an insoluble
metal oxide and a dilute acid.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Page 6 of 14
___________________________________________________________________
___________________________________________________________________
(6)
(Total 11 marks)
Q4.
(a)
Calcium chloride is made from limestone. The limestone used contains mainly
calcium carbonate and a small amount of magnesium carbonate.
(i)
In stage 1 calcium carbonate reacts with acid X to form calcium chloride.
Name acid X.
______________________________________________________________
(1)
(ii)
Stage 1 produces a concentrated solution of calcium chloride.
The solution also contains magnesium chloride.
Calcium hydroxide solution is added to remove the magnesium chloride:
MgCl2(aq)
+ Ca(OH)2(aq)
→ Mg(OH)2(s)
+ CaCl2(aq)
This is an example of a precipitation reaction.
What is the meaning of the term precipitation reaction?
______________________________________________________________
______________________________________________________________
(1)
(iii)
The magnesium hydroxide can be separated from the calcium chloride
solution.
Page 7 of 14
State how.
______________________________________________________________
______________________________________________________________
(1)
(iv)
Suggest why stage 4 is needed.
______________________________________________________________
______________________________________________________________
(1)
(v)
Name a method that can be used to change calcium chloride solution into
solid calcium chloride.
______________________________________________________________
(1)
(b)
Calcium chloride can also be made by reacting calcium with chlorine.
Calcium chloride is an ionic compound. It contains calcium ions (Ca2+).
(i)
Complete the equation for the formation of calcium ions.
Ca
→
Ca2+
+
________
(1)
(ii)
Why can the formation of calcium ions from calcium atoms be described as
oxidation?
______________________________________________________________
______________________________________________________________
(1)
(Total 7 marks)
Q5.
Limestone is used as a building material. Acid rain erodes limestone.
(a)
Limestone contains calcium carbonate.
The symbol equation for the reaction of calcium carbonate with hydrochloric acid is
shown.
CaCO3(s) + 2HCl(aq)
→ CaCl2(aq) + H2O(l) + CO2(g)
Describe a test to show that carbon dioxide is produced in this reaction.
Give the result of the test.
___________________________________________________________________
___________________________________________________________________
Page 8 of 14
___________________________________________________________________
___________________________________________________________________
(2)
(b)
Gases from vehicle exhausts produce sulfuric acid and nitric acid.
A student investigated the reaction of these two acids with calcium carbonate
(limestone).
The type of acid was changed but all other variables were kept the same.
The student measured the volume of carbon dioxide produced each minute for a
total of 10 minutes. He did this first for the reaction between dilute sulfuric acid and a
cube of calcium carbonate (limestone).
The student repeated the experiment using dilute nitric acid in place of the dilute
sulfuric acid.
The results are shown below.
(i)
State two variables that must be kept the same for this investigation.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(2)
(i)
Reacting calcium carbonate with sulfuric acid gave different results to nitric
acid.
The symbol equations for the reaction of calcium carbonate with sulfuric acid
and with nitric acid are shown below.
CaCO3(s) + H2SO4(aq)
→ CaSO4(s)
+
CaCO3(s) + 2HNO3(aq) → Ca(NO3)2(aq) +
H2O(l) + CO2(g)
H2O(l) + CO2(g)
Describe how the results for sulfuric acid are different and use the symbol
Page 9 of 14
equations to explain this difference.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(3)
(Total 7 marks)
Page 10 of 14
Mark schemes
Q1.
(a)
copper sulfate
allow CuSO4
1
water
allow H2O
1
(b)
the volume of gas stopped increasing
allow the volume of carbon dioxide stopped
increasing
allow no more fizzing / bubbling
allow no more solid left
1
(c)
all points plotted correctly
allow 1 mark for 3 or 4 correctly plotted points
allow tolerance of ± ½ a small square
2
line of best fit
1
(d)
(the decreasing concentration of sulfuric acid) decreases the rate of reaction
1
(because) frequency of particle collisions will decrease
1
[8]
Q2.
(a)
(i)
sodium hydroxide solution
1
blue
1
(ii)
barium chloride
1
white
1
(b)
fully ionised in water
1
(c)
(i)
H+ ions
1
(ii)
lower than
1
Page 11 of 14
(d)
(i)
(indicator) changed colour / goes colourless
ignore clear / discoloured
1
(ii)
13.9
or
(titration) 2
1
(iii)
13.2
ecf from (d)(ii)
1
[10]
Q3.
(a)
HNO3
1
(b)
H+
1
(c)
zinc chloride
allow ZnCl2
1
(d)
2 H3PO4 + 3 MgCO3 ⟶ Mg3(PO4)2 + 3 H2O + 3 CO2
allow 1 mark for H2O + CO2
2
(e)
Level 3: The plan would lead to the production of a valid outcome. The key steps
are identified and logically sequenced.
5-6
Level 2: The plan would not necessarily lead to a valid outcome. Most steps
are identified, but the method is not fully logically sequenced.
3-4
Level 1: The plan would not lead to a valid outcome. Some relevant steps are
identified, but links are not made clear.
1-2
No relevant content
0
Indicative content
•
use copper oxide and sulfuric acid
•
add a measured volume of sulfuric acid to a beaker
•
warm sulfuric acid
•
add copper oxide
•
stir
•
continue adding until copper oxide is in excess
•
filter
•
using a filter paper and funnel
•
to remove excess copper oxide
•
heat solution in an evaporating basin
Page 12 of 14
•
•
•
to crystallisation point
leave to crystallise
pat dry with filter paper
credit may be given for diagrams
[11]
Q4.
(a)
(i)
hydrochloric (acid) / HCl
allow phonetic spelling
ignore incorrect formula
ignore state symbols
1
(ii)
idea of a solid / insoluble substance being formed (from solutions)
accept solid / insoluble product
ignore cloudy
do not accept evaporation
1
(iii)
filtration / filter
accept decanting / centrifugation
ignore evaporate if after filtering
1
(iv)
idea of making safe (to eat)
allow remove harmful substances / organisms or sterilisation
or
idea of purification
or
idea of neutralisation
1
(v)
crystallisation
accept evaporation / heating / boiling
allow cooling
do not allow freezing / solidifying
1
(b)
(i)
2e–
accept e– + e–
ignore working out
1
(ii)
electron(s) are lost (from calcium atoms)
ignore numbers if given
do not accept any reference to oxygen
1
[7]
Q5.
Page 13 of 14
(a)
limewater or calcium hydroxide solution
1
(reacts with carbon dioxide and) turns cloudy / milky
linked to first point
if no other mark awarded ‘puts out lighted splint’ gains 1
mark
1
(b)
(i)
any two from:
•
same volume / amount of the acids
•
concentration of the acids
•
temperature
•
same surface area / size / mass / amount of calcium carbonate
•
same measuring equipment
2
(ii)
any three from:
•
(after about 4 minutes) the sulfuric acid stops reacting or nitric acid
continues to react
accept more CO2 with nitric acid at any time after 4 minutes
•
(initially) the reaction with sulfuric acid is faster
•
(the reaction stops) because calcium sulfate is a solid
allow sulfuric acid produces a solid
•
(the reaction continues) because calcium nitrate is soluble / in solution /
aqueous
allow nitric acid produces an (aqueous) solution
•
because the calcium sulfate prevents the sulfuric acid reacting with the
calcium carbonate
•
(the rate is faster) because sulfuric acid contains two hydrogens
3
[7]
Page 14 of 14