IGCSE Chemistry Paper 6 · Alternative to Practical practice papers
Core & Extended · 4 questions, Q4 = planning. Each generated paper follows the 0620 Paper 6 · Alternative to Practical format, with the same number and style of questions as the real exam, and comes with a Cambridge-style mark scheme.
Alternative to Practical papers have four questions: reading instruments, completing a results table, plotting and using a graph, and a final planning question. On the harder settings, each question adds the evaluation parts that decide top grades, such as which way an error moves a result and why each step of a method is needed.
Sample Paper 6 · Alternative to Practical questions
Question 1Structured · 11 marks
A student adds dilute hydrochloric acid of concentration 1.00 mol/dm³, 2.0 cm³ at a time from a burette, to 25.0 cm³ of aqueous sodium hydroxide in a polystyrene cup. The highest temperature after each addition is recorded in Table 1.1.
volume of acid added / cm³
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
temperature / °C
18.4
19.4
20.7
22.1
23.2
24.4
25.5
26.6
27.9
27.7
27.5
Table 1.1
(a)
Plot the results on the grid. Draw two straight lines of best fit: one through the points where the temperature rises and one through the points where it falls. Extend both lines until they cross.
Fig. 1.1
[4]
(b)
Use your graph to find the volume of acid needed to neutralise the sodium hydroxide.
[2]
(c)
Calculate the concentration of the sodium hydroxide. NaOH + HCl → NaCl + H₂O
[2]
(d)
Explain why the temperature rises and then falls.
[2]
(e)
Suggest why the end-point found from the graph is more accurate than the volume at which the highest recorded temperature occurred.
[1]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
See graph
Axes labelled with quantity and unit, temperature / °C on the y-axis and volume of acid added / cm³ on the x-axis; suitable scales so the points occupy at least half the grid B1 all points plotted correctly to within half a small square B1 two straight lines, each through its own set of points B1 both lines extended to intersect B1
4
(b)
16.0 cm³ (± 0.5)
volume at the intersection of the two lines M1 16.0 cm³ ± 0.5 A1
2
(c)
0.64 mol/dm³
moles of HCl = 1.00 × 16/1000 M1 0.64 mol/dm³ A1
2
(d)
Neutralisation is exothermic; after the end-point no more reaction, so cooler acid lowers the temperature
neutralisation is exothermic B1 after the end-point, adding cooler acid with no reaction cools the mixture B1
2
(e)
The true maximum lies between readings; the intersection uses all the points
the true maximum lies between two readings / lines use all the data B1
1
Question 2Structured · 7 marks
A student adds 1 g of different metal powders to 25 cm³ of aqueous copper(II) sulfate in a polystyrene cup and measures the highest temperature reached. Figs. #.1 and #.2 show the thermometer readings at the start and the end of the experiment with zinc.
Fig. 2.1Fig. 2.2
(a)
Use Figs. #.1 and #.2 to complete the row for zinc in Table 2.1. Then complete the temperature rise column.
metal
initial temperature / °C
highest temperature / °C
temperature rise / °C
magnesium
22.0
57.5
zinc
iron
22.0
29.0
copper
22.0
22.0
Table 2.1
[3]
(b)
Use the results to put the four metals in order of reactivity, most reactive first.
[1]
(c)
Explain why there was no temperature change with copper.
[1]
(d)
Why was a polystyrene cup used instead of a glass beaker?
[1]
(e)
Suggest one other variable that must be kept constant.
[1]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
zinc: 22.0, 35.0; rises 35.5, 13.0, 7.0, 0.0
Both readings correct to 0.5 °C B1 All rises correct B1 All recorded to 1 d.p. / nearest 0.5 B1
3
(b)
magnesium, zinc, iron, copper
magnesium > zinc > iron > copper B1
1
(c)
Copper is not more reactive than copper, so no displacement reaction occurs
No reaction / copper cannot displace itself B1
1
(d)
Polystyrene is an insulator, so it reduces thermal energy loss
Insulator / reduces heat loss B1
1
(e)
Volume/concentration of copper(II) sulfate; mass/particle size of metal
Volume or concentration of solution / mass or particle size of metal B1
1
Question 3Structured · 11 marks
A student measures the temperature of 25 cm³ of aqueous copper(II) sulfate in a polystyrene cup every minute. At 3 minutes an excess of magnesium powder is added and the mixture is stirred. Table 3.1 shows the results.
time / min
0
1
2
3
4
5
6
7
8
9
10
temperature / °C
22.7
22.4
22.7
—
45.4
44.7
44.1
43.4
42.6
42.0
41.5
Table 3.1
(a)
Plot the results on the grid. Draw a straight line through the points before 3 minutes and a straight line through the points after 3 minutes, extended back to 3 minutes.
Fig. 3.1
[4]
(b)
Use your graph to find the maximum temperature rise.
[2]
(c)
Calculate the energy released. Assume 4.2 J are needed to raise the temperature of 1 g of solution by 1 °C.
[2]
(d)
Explain why the line is extrapolated back to 3 minutes rather than using the highest temperature recorded.
[2]
(e)
Predict how the maximum temperature rise would change if the experiment were repeated with silver instead of magnesium. Explain your answer.
[1]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
See graph
Axes labelled with quantity and unit, temperature / °C on the y-axis and time / min on the x-axis; suitable scales so the points occupy at least half the grid B1 all points plotted correctly to within half a small square B1 horizontal line for 0–2 min B1 line of best fit for the cooling points extrapolated back to 3 min B1
4
(b)
23.4 °C (± 0.5)
reads both lines at 3 minutes M1 23.4 °C ± 0.5 A1
2
(c)
2460 J
25 × 4.2 × ΔT M1 2460 J A1
2
(d)
Energy is lost to the surroundings while the reaction takes place; extrapolation estimates the rise with no heat loss
thermal energy is lost while the temperature is rising B1 extrapolation gives the temperature rise at the instant of mixing B1
2
(e)
No rise: silver is less reactive than copper, so no displacement
no temperature rise, silver is less reactive than copper B1
1
Question 4Structured · 6 marks
A student carries out tests on a solution of salt X. Table 4.1 shows the results.
test
observation
Add aqueous sodium hydroxide dropwise, then in excess.
light blue precipitate, insoluble in excess
Add aqueous ammonia dropwise, then in excess.
light blue precipitate, soluble in excess giving a dark blue solution
Add aqueous sodium hydroxide and aluminium foil; warm. Test any gas with damp red litmus paper.
gas turns damp red litmus paper blue
Flame test.
blue-green flame
Table 4.1
(a)
Identify the cation in X.
[1]
(b)
Identify the anion in X.
[1]
(c)
Name salt X.
[1]
(d)
Name the gas that turns damp red litmus paper blue.
Riyaz Shaikh has mentored IGCSE, IB and A Level students for 15+ years, one-on-one, online and in Mumbai. The hardest questions on this site are the ones he uses to find a student's weak points.
Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in