IGCSEChemistry: Co-ordinated Sciences (Double Award)CIEExam QuestionsStoichiometryThe Mole & the Avogadro Constant

The Mole & the Avogadro Constant (CIE IGCSE Chemistry: Co-ordinated Sciences (Double Award))

Exam Questions

3 hours38 questions

Select a question set to download for
The Mole & the Avogadro Constant

Select an answer set to view for
The Mole & the Avogadro Constant

Easy
Medium
Hard
11 mark

Extended tier only

Which row correctly describes the mole and the value of Avogadro’s constant?

 

one mole of a substance is equal to

 one mole of a substance contains
A the substances relative atomic or molecular mass in grams  6.02 x 1023 atoms, molecules or formula units
B the substances atomic number in grams  6.02 x 1023 atoms, molecules or formula units
C the substances relative atomic or molecular mass in grams  12.04 x 1023 atoms, molecules or formula units
D the substances atomic number in grams  12.04 x 1023 atoms, molecules or formula units



    Choose your answer

    Did this page help you?

    21 mark

    Extended tier only

    Magnesium carbonate and hydrochloric acid react to produce salt, water and carbon dioxide.

    MgCO3 (s) + 2HCl (aq) → MgCl2 (aq) + H2O (l) + CO2 (g) 

    What is the volume of CO2 produced when 21 g of magnesium carbonate (Mr = 84) reacts completely with excess hydrochloric acid?

    One mole of gas occupies 24.0 dm3 at room temperature and pressure.

    • 4 dm3

    • 8 dm3

    • 6 dm3

    • 2 dm3

    Choose your answer

    Did this page help you?

    31 mark

    Extended tier only

    Calcium carbonate undergoes thermal decomposition at high temperatures to form calcium oxide and carbon dioxide.

    CaCO3 → CaO + CO2

    What mass of calcium oxide (Mr = 56) is formed when 60 g of calcium carbonate (Mr = 100) is completely decomposed?

    • 28 g

    • 18.5 g

    • 60 g

    • 33.6 g

    Choose your answer

    Did this page help you?

    11 mark

    Extended tier only

    The complete combustion of methane produces carbon dioxide and steam.

    CH4(g) + 2 O2(g) → 2 H2O(g) + CO2(g)

    Which statements are about the reaction correct?

    1 The empirical formula of methane is CH4
    2 The number of atoms in 1 mole of methane is 4 x Avogadro’s constant
    3 1 mole of methane produces 72 dm3 of gaseous products at r.t.p
    4 1 mole of methane occupies a volume of 12 dm3 at r.t.p

    • 1, 2 and 3

    • 1 and 2

    • 1 and 3

    • 2 and 4

    Choose your answer

    Did this page help you?

    21 mark

    Extended tier only

    Magnesium carbonate and hydrochloric acid react to produce salt, water and carbon dioxide.

    MgCO3 (s) + 2HCl (aq) → MgCl2 (aq) + H2O (l) + CO2 (g) 

    What is the volume of CO2 produced when 21 g of magnesium carbonate (Mr = 84) reacts completely with excess hydrochloric acid?

    One mole of gas occupies 24.0 dm3 at room temperature and pressure.

    • 4 dm3

    • 8 dm3

    • 6 dm3

    • 2 dm3

    Choose your answer

    Did this page help you?

    11 mark

    Extended tier only

    Calcium carbide and water react to produce ethyne and calcium hydroxide.

    CaC2 (s) + 2H2O (l) → C2H2 (g) + Ca(OH)2 (s)

    What is the volume of C2H2 produced, at standard temperature and pressure, when 45 g of water reacts completely with calcium carbide?

    • 72 dm3

    • 30 dm3

    • 24 dm3

    • 6 dm3

    Choose your answer

    Did this page help you?

    21 mark

    Extended tier only

    Aluminium and oxygen react to produce aluminium oxide.

    4 Al + 3 O2 → 2 Al2O3

    How many kilograms of aluminium oxide are formed when 5.4 kg of aluminium react with excess oxygen?

    • 5.4 kg

    • 88 kg

    • 10.2 kg

    • 33.6 kg

    Choose your answer

    Did this page help you?

    31 mark

    Extended tier only

    Magnesium nitride and water react to produce a precipitate of magnesium hydroxide and ammonia gas.

    Mg3N2 + 6 H2O → 3 Mg(OH)2 + 2 NH3

    How much magnesium nitride is needed to produce 87 g of the precipitate in excess water?

    • 24 g

    • 50 g

    • 30 g

    • 12 g

    Choose your answer

    Did this page help you?

    41 mark

    Extended tier only

    A chemist reacted 0.6 g of magnesium with 0.6 dm3 of oxygen in a sealed container to produce magnesium oxide.

    2Mg + O2 → 2MgO

    Which row correctly describes the limiting reactant?

      limiting reactant reason
    A Mg in excess
    B Mg is used up first
    C O2 is used up first
    D O2 in excess

      Choose your answer

      Did this page help you?