Practical Skills (OCR GCSE Chemistry A (Gateway)): Exam Questions

57 mins24 questions
11 mark

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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21 mark

What is the reading on the following thermometer?

7-1-q10-ocr-gcse-chemistry-mcq
  • 28.3 oC

  • 28.6 oC

  • 29.2 oC

  • 28.5 oC

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31 mark

Paper chromatography was used to determine if a banned preservative, X, is present in four samples obtained from four different packaged foods labelled A, B, C and D.

The results of the analysis of the foodstuffs are shown in the diagram below.

q2-easy-mcq-12-2-separation-purification-cie-igcse-chemistry

Which foodstuff contains X?

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    41 mark

    What is the correct expression for calculating the Rf value in chromatography?

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    51 mark

    Metal cations can be detected using flame tests.

    Which row correctly describes the colour of the flame for each metal cation?

     

    Li+

    K+

    Ca2+

    A

    lilac

    red

    yellow

    B

    red

    lilac

    orange-red

    C

    yellow

    orange-red

    red

    D

    red

    blue

    orange-red

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      11 mark

      A laboratory experiment to separate crude oil is shown below.

      q9-2-2-lab-experiment-for-separating-crude-oil

      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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        21 mark

        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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        31 mark

        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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        41 mark

        Below are five steps in the preparation of a soluble salt. The sentences are not in the correct order.

        1. Heat to evaporate most of the water

        2. Add solid copper(II) oxide until no more dissolves

        3. Measure out 25 cm3 of dilute sulfuric acid

        4. Leave in a warm place to cool and crystallise

        5. Filter to remove the excess solid

        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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        51 mark

        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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        61 mark

        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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        71 mark

        A student sets up the following laboratory apparatus.

        7-1-q9-ocr-gcse-chemistry-mcq-

        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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        81 mark

        A student investigates the reaction between sodium thiosulfate and hydrochloric acid.

        Look at the diagram below. It shows the apparatus he uses.

        q4-paper-2-specimen-2016-ocr-gcse-chem
        • After a time he cannot see the cross because the liquid in the conical flask goes cloudy. The student measures the time taken until the cross cannot be seen.

        • He does the experiment four times. For each experiment he uses a different concentration of sodium thiosulfate solution.

        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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        91 mark

        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?

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        • % difference = fraction numerator left parenthesis student ’ straight s space value space in space º straight C right parenthesis space – space 85 space degree straight C over denominator 85 space degree straight C end fraction

        • % difference = fraction numerator 85 space degree straight C space – space left parenthesis student ’ straight s space value space in space degree straight C right parenthesis over denominator 85 space degree straight C end fraction

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        1
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        1 mark

        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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        21 mark

        A student titrated sodium carbonate solution against 25 cm3 of hydrochloric acid. 

        They used methyl orange as an indicator.

        What is the colour changed observed at the end point?

        • red to yellow

        • yellow to orange

        • yellow to red

        • red to orange

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        31 mark

        A student investigates the electrolysis of aqueous copper(II) sulfate.

        Which test would correctly identify the gas produced at the anode?

        • A burning splint gives a squeaky pop sound

        • Damp litmus paper bleaches white

        • A glowing splint relights

        • Limewater turns cloudy

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        41 mark

        A yellow solid, W is soluble in water. Which method of separation can be used to obtain the solid W from an aqueous solution?

        • Neutralisation

        • Chromatography

        • Distillation

        • Crystallisation

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        51 mark

        A student tested a solution of compound X.

        The results are shown below.

        Test

        Result

        Add dilute nitric acid followed by silver nitrate solution

        White precipitate

        Add sodium hydroxide solution

        Green precipitate

        Which two ions are present in compound X?

        • Fe3+ and Cl-

        • Fe3+ and SO42-

        • Fe2+ and Cl-

        • Fe2+ and SO42-

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