Chemistry • Year 11 • Module 3 • Lesson 5
Acid-Base & Acid-Carbonate Reactions
Lock in the core vocabulary, reaction-type recognition, salt identification rules, and the SWC mnemonic before tackling exam questions.
1. Term–definition match
Write the matching term from this list into the right-hand column. Terms: acid, base, alkali, neutralisation, salt, net ionic equation, carbonate, acid-carbonate reaction, SWC products, Arrhenius definition. 10 marks (1 each)
| # | Definition | Matching term |
|---|---|---|
| 1.1 | A substance that produces H+ ions in water (Arrhenius) or donates a proton (Brønsted-Lowry). | |
| 1.2 | A substance that produces OH− ions in water (Arrhenius) or accepts a proton (Brønsted-Lowry). | |
| 1.3 | A soluble base that forms OH− ions in water; e.g. NaOH, Ca(OH)2. | |
| 1.4 | The reaction between an acid and a base: acid + base → salt + water. | |
| 1.5 | An ionic compound formed from the cation of a base and the anion of an acid. | |
| 1.6 | Shows only the ions that actually change during a reaction; spectator ions are removed. | |
| 1.7 | An ion with the formula CO32−; its presence leads to the formation of CO2 gas when treated with acid. | |
| 1.8 | Acid + carbonate → salt + water + CO2(g); three products always formed. | |
| 1.9 | The memory aid that lists the three fixed products of every acid-carbonate reaction: Salt, Water, Carbon dioxide. | |
| 1.10 | The model proposed in 1884 stating that acids produce H+ and bases produce OH− in water. |
2. True or false — with correction
Circle T or F. If false, write the corrected statement on the line. 10 marks (1 T/F + 1 correction)
2.1 The net ionic equation for any strong acid reacting with any strong base is H+(aq) + OH−(aq) → H2O(l). T / F
2.2 When an acid reacts with a carbonate, CO(g) is produced as the gaseous carbon product. T / F
2.3 The salt formed when HCl reacts with NaOH is NaCl (sodium chloride). T / F
2.4 Mylanta (active ingredient: Mg(OH)2) produces CO2 gas when it neutralises stomach acid. T / F
2.5 The anion of the salt in any neutralisation reaction always comes from the base. T / F
3. Identify the salt and reaction type
For each acid-base pair, state (a) the reaction type, (b) the name and formula of the salt formed, and (c) one other product. Do not write the balanced equation yet — just identify. 12 marks (2 each)
3.1 HNO3(aq) + KOH(aq) →
(a) Reaction type:
(b) Salt name and formula:
(c) Other product(s):
3.2 H2SO4(aq) + Ca(OH)2(aq) →
(a) Reaction type:
(b) Salt name and formula:
(c) Other product(s):
3.3 HCl(aq) + CaCO3(s) →
(a) Reaction type:
(b) Salt name and formula:
(c) Other product(s):
3.4 HNO3(aq) + Na2CO3(aq) →
(a) Reaction type:
(b) Salt name and formula:
(c) Other product(s):
3.5 HCl(aq) + NaHCO3(aq) →
(a) Reaction type:
(b) Salt name and formula:
(c) Other product(s):
3.6 H2SO4(aq) + 2NaOH(aq) →
(a) Reaction type:
(b) Salt name and formula:
(c) Other product(s):
4. Cloze — fill the blank
Complete the paragraph using the word bank. Each term is used once only. 8 marks (1 per blank)
Word bank: neutralisation • salt • water • CO2 • spectator • SWC • H+ • OH−
When an acid reacts with a base, the process is called _______________ (1). The H+ ion from the acid combines with the _______________ (2) ion from the base to form _______________ (3). The remaining ions form a _______________ (4). Because the Na+ and Cl− ions in, say, HCl + NaOH do not change during the reaction, they are called _______________ (5) ions and are removed from the net ionic equation. The universal net ionic form is therefore _______________ (6) + OH− → H2O.
When acid meets a carbonate, the mnemonic _______________ (7) lists the three products: salt, water, and _______________ (8) gas.
5. Build a concept map
Draw labelled arrows between the five terms below to show how they connect. Each arrow must carry a linking phrase (e.g. "produces", "is a type of", "reacts with"). Aim for at least 5 labelled arrows. 5 marks
Supplied terms: acid • base • salt • carbonate • CO2.
Q1 — Term-definition matches
1.1 acid • 1.2 base • 1.3 alkali • 1.4 neutralisation • 1.5 salt • 1.6 net ionic equation • 1.7 carbonate • 1.8 acid-carbonate reaction • 1.9 SWC products • 1.10 Arrhenius definition.
Q2 — True / false with correction
2.1 True. H+(aq) + OH−(aq) → H2O(l) is universal for all strong acid-strong base reactions.
2.2 False. Correction: The gas produced is CO2 (carbon dioxide), not CO. The carbon in CO32− is already at oxidation state +4, so only CO2 is possible.
2.3 True. Na+ (from base) + Cl− (from acid) = NaCl.
2.4 False. Correction: Mg(OH)2 is a hydroxide base, not a carbonate. It undergoes neutralisation (acid + base → salt + water) and produces NO CO2.
2.5 False. Correction: The anion of the salt comes from the acid, not the base. The cation comes from the base.
Q3 — Salt identification
3.1 (a) Neutralisation. (b) Potassium nitrate, KNO3. (c) Water, H2O(l).
3.2 (a) Neutralisation. (b) Calcium sulfate, CaSO4. (c) Water, H2O(l).
3.3 (a) Acid-carbonate reaction. (b) Calcium chloride, CaCl2. (c) Water, H2O(l) and carbon dioxide, CO2(g).
3.4 (a) Acid-carbonate reaction. (b) Sodium nitrate, NaNO3. (c) Water, H2O(l) and carbon dioxide, CO2(g).
3.5 (a) Acid-hydrogen carbonate reaction. (b) Sodium chloride, NaCl. (c) Water, H2O(l) and carbon dioxide, CO2(g).
3.6 (a) Neutralisation. (b) Sodium sulfate, Na2SO4. (c) Water, H2O(l).
Q4 — Cloze answers
(1) neutralisation • (2) OH− • (3) water • (4) salt • (5) spectator • (6) H+ • (7) SWC • (8) CO2.
Q5 — Sample concept map
Acceptable labelled arrows include:
- acid — reacts with → base — to produce → salt
- acid — reacts with → carbonate — to produce → salt
- carbonate — when reacting with acid releases → CO2
- carbonate — is a type of → base
- base — does not produce → CO2 (distinguishing arrow)
Award 1 mark per correctly labelled arrow that respects causal direction. Five arrows required for full marks.