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InkFlaskCambridge IGCSE

Pupil sheet · Acids, bases and indicators

Acids, bases and indicators — return questions

Name ______________________ Date ____________

Use one to two weeks after the lessons. Keep the notes and the lesson closed.

1. state

A colourless solution W turns thymolphthalein blue. Fill in the gaps. Solution W is an alkali, so it contains (1) ___ ions. It turns litmus (2) ___ and methyl orange (3) ___. Its pH is (4) ___ 7.

(1)

(2)

(3)

(4)

2. identify

Match each reaction to its products.

Write the number of the matching option.

  1. a salt, water and ammonia
  2. a salt and hydrogen
  3. a salt and water
  4. a salt, water and carbon dioxide
  • 1. Zinc oxide + hydrochloric acid: ______
  • 2. Magnesium carbonate + nitric acid: ______
  • 3. Ammonium nitrate + sodium hydroxide, warmed: ______
  • 4. Aluminium + hydrochloric acid: ______

3. state

Supplement. Benzoic acid, C6H5COOH, is a weak acid used to keep food from going off. Fill in the gaps. C6H5COOH(aq) (1) ___ (2) ___ + C6H5COO−(aq). In water benzoic acid is (3) ___ dissociated. When it reacts with sodium hydroxide, benzoic acid is a proton (4) ___, and the hydroxide ion is a proton (5) ___.

(1)

(2)

(3)

(4)

(5)