Which statement correctly describes a test for oxygen gas?
A lighted splint makes a squeaky pop
Limewater turns milky
A glowing splint re-lights
Damp litmus paper is bleached
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Which statement correctly describes a test for oxygen gas?
A lighted splint makes a squeaky pop
Limewater turns milky
A glowing splint re-lights
Damp litmus paper is bleached
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What is the reading on the following thermometer?
28.3 oC
28.6 oC
29.2 oC
28.5 oC
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A laboratory experiment to separate crude oil is shown below.
Which row is correct?
The process taking place at X | The process taking place at Y | |
A | decomposition | condensation |
B | evaporation | reduction |
C | distillation | reduction |
D | evaporation | condensation |
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A student adds a few drops of dilute nitric acid followed by a few drops of silver nitrate solution to a test tube containing an unknown colourless solution. A white precipitate is seen.
What ions could be present in the solution?
Ammonium ions
Chloride ions
Sulfate ions
Magnesium ions
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A student adds some drops of bromine water to a solution of potassium iodide.
Which statement is correct?
The solution turns brown
A yellow precipitate forms
The bromine water turns the solution orange
The bromine water decolourises the solution
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Below are five steps in the preparation of a soluble salt. The sentences are not in the correct order.
What is the correct order of the sentences?
5,1,4,3,2
2,5,3,1,4
3,2,5,1,4
5,1,3,2,4
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What is the correct expression for calculating the Rf value in chromatography?
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A student wants to investigate the effect of surface area on the rate of reaction between marble chips and dilute acid.
What pieces of apparatus would be essential to this investigation?
Burette, beaker, pipette
Ruler, thermometer, test tube
Balance, measuring cylinder, stopwatch
Filter funnel, evaporating basin, Bunsen burner
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Aqueous copper(II) sulfate solution can be electrolysed using carbon electrodes.
Which statement is true about the reaction?
A pink coating is seen around the positive electrode
Gases are given off at both electrodes
The gas given off at the positive electrode can be tested with a burning splint
The blue colour of the solution slowly fades
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A student sets up the following laboratory apparatus.
Which reaction could the student be investigating?
Cracking liquid paraffin
The effect of concentration in the reaction between marble chips and dilute hydrochloric acid
The neutralisation of dilute hydrochloric acid by solid calcium hydroxide
The displacement reaction between chlorine solution and aqueous potassium bromide
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A student investigates the reaction between sodium thiosulfate and hydrochloric acid.
Look at the diagram below. It shows the apparatus he uses.
Which of the following must not be changed to do a fair test?
Concentration of sodium thiosulfate
Stop-clock or timer
Total volume of the reaction mixture
Volume of sodium thiosulfate added
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A student wants to test the purity of a liquid by testing its boiling point.
The actual boiling point of the pure liquid is 85 °C.
Which equation represents the percentage (%) difference between the student’s value and the actual value?
% difference = 100 ×
% difference = 100 ×
% difference =
% difference =
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On a chromatogram, a substance has an Rf value of 0.68.
If the solvent front travels 9 cm from the baseline, at what distance from the baseline will the spot be found.
0.1
5.1
6.0
6.1
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