Page 102 - Chemistry_Form_2

Chemistry
for Secondary Schools

Iron is the reducing agent since it loses electrons to chlorine atoms. Chlorine gas
is the oxidising agent since it accepts or gains electrons from iron.
Neutralisation reaction

A neutralisation reaction is chemical reaction between an acid and a base to give
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salt and water as the products. For example

Neutralisation reactions are common in everyday life, particularly in personal
care, medicine and agriculture. For example, toothpaste neutralises acid produced
by bacteria in the mouth. Antacids neutralise stomach acid.

Exercise 4.2

1. Differentiate oxidation from reduction in terms of electron transfer and
changes in oxidation states.

2. Write a balanced chemical equation for each of the following reactions:
(a) Zinc reacts with silver nitrate solution to produce zinc nitrate and silver.
(b) Aqueous potassium iodide reacts with aqueous solution of lead(II)
nitrate to produce potassium nitrate and lead(II) iodide.
3. Identify the type of reaction in each of the following chemical equations:

Explain your answer.
(a)

(b)
(c)
(d)

4. A student mixed lead metal with a solution of magnesium chloride but
observed no reaction. However, when magnesium metal was added to
lead(II) nitrate solution, a reaction occurred. Explain why one reaction
occurred while the other did not.
5. The school laboratory has solutions of barium chloride (BaCl ), sodium
2
sulfate (Na SO ), and potassium nitrate (KNO ).
2 4 3
(a) Which pair of solutions will produce precipitates when mixed?
(b) Describe a simple experiment to confirm the presence of a precipitate.
6. Explain how corrosion is related to redox reactions. Suggest one way of
preventing iron from rusting.

Student’s Book Form Two 95

01/08/2025 11:20:59
CHEMISTRY FORM TWO NEW 2025 DUMMY.indd 95 01/08/2025 11:20:59
CHEMISTRY FORM TWO NEW 2025 DUMMY.indd 95