IGCSE chemistry section 4 c
Reactions of acids: ionic equations
1. Hydrochloric acid reacts with zinc.
(a) Which one is the correct word equation for this reaction?
A. hydrochloric acid + zinc  zinc chloride + water
B. hydrochloric acid + zinc  zinc chloride + hydrogen
C. hydrochloric acid + zinc  zinc chloride + oxygen
D. hydrochloric acid + zinc  zinc chlorate + water
(b) Give two reasons why you think your answer to 1 (a) is the correct answer.
(c) Which one is the correct symbol equation for this reaction?
A. HCl (aq)
+
Zn (s)
 ZnCl (aq)
B. 2HCl (aq)
+
Zn (s)
 2ZnCl (aq)
+
H2 (g)
C. 2HCl (aq)
+
Zn (s)
 ZnCl2 (aq)
+
H2 (g)
D. 2HCl (aq)
+
Zn (s)
 ZnCl2 (s)
+
+
H2 (g)
H (g)
(d) Give three reasons why you think your answer to 1 (c) is the correct answer.
(e) A full ionic equation shows all the ions that are involved in a reaction separately
and not as part of a compound (unless a precipitate is formed). The full ionic
equation also shows any atoms (e.g. metal atoms) or molecules (e.g. water) that
are involved in the reaction. Ionic equations must be balanced in terms of particles
as well as charges.
Which one is the correct full ionic equation for this reaction?
A. H+(aq) + Cl- (aq)
B. 2H+(aq) + Cl- (aq)
+
Zn (s)
+
Zn (s)
 Zn2+ (aq) + Cl- (aq) +
H2 (g)
 Zn2+ (aq) + Cl- (aq) +
C. 2H+(aq) + 2Cl- (aq)
+
Zn (s)
 ZnCl2 (aq) +
D. 2H+(aq) + 2Cl- (aq)
+
Zn (s)
 Zn2+ (aq) + 2Cl- (aq) +
H2 (g)
H2 (g)
H2 (g)
(f) A net ionic equation does not include the ions that do not change during the
reaction (spectator ions). Write the net ionic equation for this reaction.
2. (a) Write the symbol equation, full ionic and net ionic equation for magnesium
reacting with sulphuric acid.
(b) Compare the net ionic equation you answered in 1(f) with the net ionic equation
you answered in 2(a).
3. (a) Write the symbol equation, full ionic and net ionic equation for sodium
hydroxide reacting with nitric acid.
(b) Write the symbol equation, full ionic and net ionic equation for sodium
hydroxide reacting with sulphuric acid.
(c) Compare and contrast the net ionic equation you answered in 3(a) with the net
ionic equation you answered in 3(b).
(d) What type of reaction do we call the reactions in 3(a) and 3(b)?
4. (a) Write the symbol equation, full ionic and net ionic equation for magnesium oxide
reacting with hydrochloric acid.
(b) Write the symbol equation, full ionic and net ionic equation for magnesium oxide
reacting with sulphuric acid.
(c) Compare and contrast the net ionic equation you answered in 4 (a) with the net
ionic equation you answered in 4(b).
(d) What type of reaction do we call the reactions in 4(a) and 4(b)?
5. (a) Write the symbol equation, full ionic and net ionic equation for magnesium carbonate
reacting with hydrochloric acid.
(b) Write the symbol equation, full ionic and net ionic equation for magnesium carbonate
reacting with sulphuric acid.
(c) Compare and contrast the net ionic equation you answered in 4 (a) with the net
ionic equation you answered in 4(b).
(d) What type of reaction do we call the reactions in 4(a) and 4(b)?