IGCSE 2020 0620 Specimen Paper 6 (pdf)
- The diagram shows the apparatus used to prepare a dry sample of a gas. The gas is more dense
(a) Complete the boxes to name the apparatus.
(b) Identify one mistake in the apparatus.
(c) Suggest a reason why the gas is passed through concentrated sulfuric acid.
- A student investigated the rate of reaction between excess magnesium and two different dilute
acids, X and Y.
Two experiments were carried out.
The apparatus was set up as shown in the diagram.
Using a measuring cylinder, 50cm3
of dilute acid X was poured into the conical flask.
0.5g of magnesium ribbon was added to the conical flask and the bung added.
The timer was started and the volume of gas collected in the measuring cylinder was measured
every 30 seconds for three minutes.
(a) Use the measuring cylinder diagrams to record the volumes of gas collected.
Experiment 1 was repeated using 50cm of dilute acid Y.
(b) Use the measuring cylinder diagrams to record the volumes of gas collected.
(c) Plot the results for both experiments on the grid below. For each set of results, draw a
smooth line graph. Indicate clearly which line represents Experiment 1 and which line
represents Experiment 2.
(d) State which experiment had the faster rate of reaction and suggest why the rate was faster in
(e) From your graph, deduce the time required to collect 25cm3 of gas in Experiment 1.
Show clearly on the graph how you worked out your answer.
(f) The rate of this reaction can be calculated using:
For the experiment with the higher rate, calculate the rate of reaction for the first 30 seconds
of the reaction. Deduce the units.
(g) Give one advantage and one disadvantage of using a measuring cylinder to add the acids to
(h) Suggest and explain one improvement to this experiment.
- Concentrated aqueous sodium chloride was broken down by electricity using the apparatus
(a) Suggest a suitable material from which to make the electrodes.
(b) Gas A is chlorine. Give a test for chlorine.
(c) Gas B pops when tested with a lighted splint. What is gas B?
- Solid E was analysed. E was an aluminium salt. Some of the observations are shown below.
(a) A little of solid E was dissolved in distilled water.
The solution was divided into four test-tubes and the following tests were carried out.
Complete the observations for tests 2 and 3.
(i) test 2
Drops of aqueous sodium hydroxide were added to the first test-tube.
(ii) Excess sodium hydroxide was then added.
(iii) test 3
Drops of aqueous ammonia solution were added to the second test-tube. Excess ammonia solution was then added.
Two further tests are carried out and the following observations made.
(b) What does test 1 tell you about solid E?
(c) Identify the gas given off in test 5.
(d) What conclusions can you draw about solid E?
(e) Test 5 states that the mixture should be warmed carefully.
In terms of safety, explain why it is necessary to warm carefully.
- E-numbers identify chemicals which are added to foods.
(a) E210 is benzoic acid. How could you show that a solution of benzoic acid is a weak acid?
(b) E110 is Sunset Yellow.
Outline a method you could use to show the presence of E110 in a food colouring.
You may draw a diagram to help answer the question.
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