Predicting Chemical Reactions (OCR Gateway GCSE Chemistry: Combined Science)

Exam Questions

50 mins25 questions
11 mark

Lithium, sodium and potassium are Group 1 elements.

What happens when these elements are added to water?

  • Some float and carbon dioxide gas and an alkaline solution are made.

  • Some float and hydrogen gas and an alkaline solution are made.

  • They all float and hydrogen gas and an acidic solution are made.

  • They all float and hydrogen gas and an alkaline solution are made.

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21 mark

Which of these elements is a transition metal?

  • Calcium

  • Caesium

  • Carbon

  • Cobalt

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31 mark

The bar chart shows the melting points of Group 1 elements.

q7-paper-1-specimen-2016-ocr-gcse-chemistry

What are the melting points of rubidium and caesium?

  Melting point of rubidium (°C) Melting point of caesium (°C)
A 39 29
B 40 25
C 29 41
D 41 25

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    11 mark

    Astatine is found below iodine in Group 7 of the periodic table.

    What is its formula and state at room temperature?

      Formula State at room temperature 
     A At gas
     B At solid
     C At2 liquid
     D At2 solid

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      21 mark

      When sodium reacts with water an alkaline solution is formed.

      Which statement about why this happens it true?

      • It contains an ionic compound

      • It contains hydroxide ions

      • It contains water

      • Hydrogen gas is made 

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      31 mark

      A student carried out a displacement reaction using an unknown halogen and a salt containing a halide ion.

      As the reaction progressed they observed the formation of a dark brown solution.

      Which halogen and salt did the students react together?  

      • Potassium iodide + bromine

      • Potassium bromide + chlorine

      • Potassium chloride + bromine

      • Potassium chloride + iodine

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      41 mark

      The diagram shows the electron structures of some elements. 

      4-1_q6-ocr-gcse-mcq-chemistry

      Which two elements have similar chemical properties?

      • A and B

      • A and C

      • B and C 

      • B and D 

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      51 mark

      Which statement about noble gases is not correct?

      • They are diatomic

      • They have low densities 

      • Their boiling points increase going down the group 

      • They are unreactive

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      61 mark

      Which statement explains why Group 1 metals get more reactive further down the group?

      • There is an increasing attraction between the outer electron and nucleus

      • There is less shielding of the outer electron so it is easier to lose

      • There is a decreasing attraction between the outer electron and nucleus so the electron is more easily lost

      • The outer electron is closer to the nucleus and harder to lose 

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      71 mark

      A student was investigating the reactivity of different metals in hydrochloric acid. 

      q3-4-1-investigating-reactivity-of-different-metals

      Which statement about the results is true?

      • Calcium is more reactive than magnesium because its outer electrons are less easily lost

      • Copper does not react because it is less reactive than hydrogen

      • Magnesium is more reactive than zinc because it more readily forms negative ions

      • Zinc reacts with the HCl to form zinc hydroxide and hydrogen gas 

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      81 mark

      The boiling point of the halogens increases down Group 7.

      Which statement explains why?

      • The covalent bonds get stronger going down the group and require more energy to overcome

      • The intermolecular forces get stronger going down the group and require more energy to overcome

      • The intermolecular forces get weaker going down the group and require less energy to overcome

      • The covalent bonds get weaker going down the group and require less energy to overcome

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      91 mark

      Lithium, sodium and potassium all react with water.

      In all three reactions the same gas is produced.

      What is the name of the gas?

      • Carbon dioxide

      • Chlorine

      • Hydrogen

      • Oxygen

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      101 mark

      The list shows part of the reactivity series of metals including carbon.

      Sodium
      Lithium
      Calcium
      Magnesium
      Aluminium
      Carbon
      Zinc
      Iron
      Tin
      Lead

      Which row of the table correctly describes how the metals are extracted from their ores?

        Metals extracted by electrolysis Metals extracted by heating with carbon
      A Sodium, Magnesium, Zinc Aluminium, Iron, Tin
      B Aluminium, Zinc, Iron Lead, Tin
      C Calcium, Magnesium, Aluminium Sodium, Iron, Tin
      D Sodium, Calcium, Magnesium Lead, Tin, Zinc

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        111 mark

        Which statement describes the properties of transition metals?

        • High melting point, shiny when freshly cut and brittle.

        • Good conductors of electricity, low density and low melting point.

        • Good conductors of electricity, strong and malleable.

        • Strong, malleable and low density.

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        121 mark

        Zinc, Zn, reacts with copper sulfate solution, CuSO4.

        Zn (s) + CuSO4 (aq) → ZnSO4 (aq) + Cu (s)

        What type of reaction is this?

        • Combustion

        • Displacement

        • Neutralisation

        • Thermal decomposition

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        131 mark

        Which statement is correct for a Group 1 element?

        • It dissolves in water to form a bleach.

        • It is an inert gas.

        • It is a non-metal.

        • It reacts with water to form hydrogen.

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        141 mark

        A student reacts some metals with different salt solutions and records her results.

        She places a tick () in her results table if she sees a chemical change and a cross (×) if there is no reaction.

        Some of the boxes are blanked out.

          Magnesium chloride Silver nitrate Copper(II) sulfate Iron(II) sulfate
        Magnesium  
        Silver ×   × ×
        Copper ×   ×
        Iron ×  


        What is the order of reactivity (most reactive to least reactive) of these four metals?

        • Iron, silver, magnesium, copper

        • Magnesium, copper, iron, silver

        • Magnesium, iron, copper, silver

        • Silver, copper, iron, magnesium

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        151 mark

        A student reacts some metals with different salt solutions and records her results.

        She places a tick () in her results table if she sees a chemical change and a cross () if there is no reaction.

        Some of the boxes are blanked out.

          Magnesium chloride Silver nitrate Copper(II) sulfate Iron(II) sulfate
        Magnesium  
        Silver  
        Copper  
        Iron  


        Which metal has the least tendency to form a positive ion?

        • Copper

        • Iron

        • Magnesium

        • Silver

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        161 mark

        Look at the data about four elements.

        Element Melting point
        (°C)
        Density
        (g / cm3)
        Ions formed
        A 98 0.97 A+
        B –101 0.0032 B
        C 1535 7.9 C2+, C3+
        D 660 2.7 D3+


        Which element is a transition element?

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          171 mark

          Group 1 elements get more reactive down the group.

          Which statement explains why?

          • The outer electron is closer to the nucleus and lost more easily.

          • The outer electron is further from the nucleus and lost more easily.

          • There is less shielding from the inner electrons.

          • There is more attraction between the nucleus and the outer electron down the group.

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          11 mark

          Chlorine can displace iodine from iodide ions.

          Which equation represents this reaction?

          • Cl + I → Cl + I

          • Cl + I2 → 2I + Cl2

          • Cl2 + 2I → 2Cl+ I2

          • Cl2 + I → 2Cl + I

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