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Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter

Acids, Alkalis and Titrations

83 practice questions

Start practising (83 questions)

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Practice questions

41–50 of 83

  1. Question 41

    2 marks · Easy

    Magnesium hydroxide (Mg(OH)_2) is often used as an antacid. It does not dissolve well in water, but any dissolved part is alkaline. Explain why a solution of magnesium hydroxide is alkaline.

    Answer and see the solution →

  2. Question 42

    1 mark · Easy

    Name a substance, other than ammonia, that forms an alkaline solution when dissolved in water.

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  3. Question 43

    3 marks · Easy

    Read the passage and answer the questions below. Acids release hydrogen ions (H^+) in water, making the solution acidic.

    (a)

    Name the ion formed in solution when hydrochloric acid is added to water.

    [1 mark]
    (b)

    Give the symbol for this ion.

    [1 mark]
    (c)

    Explain, using the equation, what happens when HCl is dissolved in water.

    [1 mark]
    Answer and see the solution →

  4. Question 44

    3 marks · Easy

    The following table shows the formulae of several acids. Use the table to answer the questions below.

    Table 1. Some common acids and their formulae.
    AcidFormula
    Hydrochloric acidHCl
    Nitric acidHNO₃
    Sulfuric acidH₂SO₄
    Phosphoric acidH₃PO₄
    Ethanoic acidCH₃COOH
    (a)

    Identify the ion that all acids in the table produce when dissolved in water.

    [1 mark]
    (b)

    State the chemical symbol and charge of this ion.

    [1 mark]
    (c)

    Explain, using the formulae in the table, how you know that each acid can form this ion.

    [1 mark]
    Answer and see the solution →

  5. Question 45

    2 marks · Easy

    A student dissolves 0.20 mol of sodium carbonate (Na_2CO_3) in enough water to make 1.0 dm³ of solution. Sodium carbonate forms an alkaline solution because it reacts to produce hydroxide ions.

    Calculate the concentration of carbonate ions (CO_3^{2-}) present in the solution. Give your answer in mol/dm³.

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  6. Question 46

    2 marks · Normal

    State the name and the formula of the ion responsible for acidity in aqueous solutions.

    (a)

    Name of the ion:

    [1 mark]
    (b)

    Formula of the ion:

    [1 mark]
    Answer and see the solution →

  7. Question 47

    4 marks · Normal

    Potassium carbonate and ammonia both form alkaline solutions in water.

    (a)

    Write a balanced chemical equation to show how ammonia forms an alkaline solution when dissolved in water.

    [2 marks]
    (b)

    State the name and formula of the ion responsible for alkalinity in these solutions.

    [2 marks]
    Answer and see the solution →

  8. Question 48

    3 marks · Normal

    Explain why a solution of sodium carbonate in water is alkaline, even though sodium carbonate does not contain hydroxide ions in its original formula.

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  9. Question 49

    4 marks · Normal

    The following table shows the concentration of hydrogen ions in different solutions.

    Solution[H^+] (mol/dm³)
    A1.0 × 10^{-2}
    B1.0 × 10^{-6}
    C1.0 × 10^{-4}
    D1.0 × 10^{-8}
    (a)

    Which solution is the most acidic? Explain your answer.

    [2 marks]
    (b)

    Which solution is likely to have a pH above 7? Give the letter.

    [1 mark]
    (c)

    State the relationship between hydrogen ion concentration and acidity.

    [1 mark]
    Answer and see the solution →

  10. Question 50

    1 mark · Normal

    Which of the following substances forms an alkaline solution by reacting with water to produce hydroxide ions?

    1. A.Sodium chloride
    2. B.Potassium carbonate
    3. C.Calcium sulfate
    4. D.Ethanoic acid
    Answer and check →