Pearson Edexcel International GCSE in Chemistry · 4CH1 · Free · no account needed
Solubility Rules and Proton Transfer — exam questions
12 original Incandio exam-style questions on Solubility Rules and Proton Transfer, 26 marks, about 26 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for Solubility Rules and Proton Transfer — the lesson that teaches it. Read the lesson first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
7 command words run through this set, and on Pearson Edexcel International GCSE Chemistry each one means something precise. Answering the wrong command is the commonest way a candidate who understands the lesson still loses the mark.
- Which (1 mark)
- one option chosen from the set given
- State (1 mark)
- one precise fact, no justification
- Give (1–2 marks)
- a short factual answer — the most common chemistry command
- Describe (2–5 marks)
- developed, linked statements of what happens or what is observed Misread as: giving one bare observation where the tariff asked for a developed account
- Explain (2–4 marks)
- the reason, in terms of particles, bonding, energy or equilibrium Misread as: describing the observation without giving the chemistry that causes it
- Suggest (1–3 marks)
- a plausible answer applying taught chemistry to an unfamiliar substance
- Name (1 mark)
- the correct chemical name
Assessed on Paper 1 (4CH1/1C) and Paper 2 (4CH1/2C), against AO1, AO2, AO3.
Where these sit in the specification
Pearson Edexcel International GCSE Chemistry (4CH1) — statements 2.36 · 2.34 · 2.35. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 12 questions
Answer them on paper, then open the lesson's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
-
Table 1 — pairs of solutions mixed together Mixture First solution Second solution Observation 1 sodium chloride potassium nitrate no change 2 silver nitrate sodium chloride white precipitate 3 barium chloride sodium sulfate white precipitate 4 sodium carbonate potassium hydroxide no change Solubility rules — All sodium, potassium and ammonium salts are soluble. All nitrates are soluble. Chlorides are soluble except silver and lead. Sulfates are soluble except barium, calcium and lead. Carbonates and hydroxides are insoluble except sodium, potassium and ammonium.
(a)
(1)Name
Name the white precipitate formed in mixture 2 of Table 1.
Table 1 — pairs of solutions mixed together Mixture First solution Second solution Observation 1 sodium chloride potassium nitrate no change 2 silver nitrate sodium chloride white precipitate 3 barium chloride sodium sulfate white precipitate 4 sodium carbonate potassium hydroxide no change Solubility rules — All sodium, potassium and ammonium salts are soluble. All nitrates are soluble. Chlorides are soluble except silver and lead. Sulfates are soluble except barium, calcium and lead. Carbonates and hydroxides are insoluble except sodium, potassium and ammonium.
(b)
(2)Explain
Explain why no precipitate forms in mixture 1 of Table 1.
Table 1 — pairs of solutions mixed together Mixture First solution Second solution Observation 1 sodium chloride potassium nitrate no change 2 silver nitrate sodium chloride white precipitate 3 barium chloride sodium sulfate white precipitate 4 sodium carbonate potassium hydroxide no change Solubility rules — All sodium, potassium and ammonium salts are soluble. All nitrates are soluble. Chlorides are soluble except silver and lead. Sulfates are soluble except barium, calcium and lead. Carbonates and hydroxides are insoluble except sodium, potassium and ammonium.
(c)
(3)Explain
Explain why mixture 3 in Table 1 gives a precipitate but mixture 4 does not.
Table 1 — pairs of solutions mixed together Mixture First solution Second solution Observation 1 sodium chloride potassium nitrate no change 2 silver nitrate sodium chloride white precipitate 3 barium chloride sodium sulfate white precipitate 4 sodium carbonate potassium hydroxide no change Solubility rules — All sodium, potassium and ammonium salts are soluble. All nitrates are soluble. Chlorides are soluble except silver and lead. Sulfates are soluble except barium, calcium and lead. Carbonates and hydroxides are insoluble except sodium, potassium and ammonium.
(d)
(3)Suggest
Suggest two solutions that could be mixed to make lead(II) iodide, given that iodides follow the same rule as chlorides.
Table 1 — pairs of solutions mixed together Mixture First solution Second solution Observation 1 sodium chloride potassium nitrate no change 2 silver nitrate sodium chloride white precipitate 3 barium chloride sodium sulfate white precipitate 4 sodium carbonate potassium hydroxide no change Solubility rules — All sodium, potassium and ammonium salts are soluble. All nitrates are soluble. Chlorides are soluble except silver and lead. Sulfates are soluble except barium, calcium and lead. Carbonates and hydroxides are insoluble except sodium, potassium and ammonium.
(Total for Question 1 = 9 marks)
-
(1)Which
Which describes an acid in terms of proton transfer?
Description A a proton acceptor B a proton donor C an electron donor D an electron acceptor (Total for Question 2 = 1 mark)
-
(1)State
State whether calcium carbonate is soluble or insoluble in water.
Solubility rules — All sodium, potassium and ammonium salts are soluble. All nitrates are soluble. Chlorides are soluble except silver and lead. Sulfates are soluble except barium, calcium and lead. Carbonates and hydroxides are insoluble except sodium, potassium and ammonium.
(Total for Question 3 = 1 mark)
-
(1)Give
Give the particle that an H⁺ ion consists of.
(Total for Question 4 = 1 mark)
-
(2)Describe
Describe what happens to a proton when hydrochloric acid reacts with sodium hydroxide solution.
(Total for Question 5 = 2 marks)
-
(3)Explain
Explain how the solubility rules can be used to predict whether mixing two solutions will produce a precipitate.
Solubility rules — All sodium, potassium and ammonium salts are soluble. All nitrates are soluble. Chlorides are soluble except silver and lead. Sulfates are soluble except barium, calcium and lead. Carbonates and hydroxides are insoluble except sodium, potassium and ammonium.
(Total for Question 6 = 3 marks)
-
(2)Explain
Explain why ammonia is described as a base even though it contains no hydroxide ions.
(Total for Question 7 = 2 marks)
-
(3)Suggest
Suggest why every compound used to prepare an insoluble salt must itself be soluble.
Solubility rules — All sodium, potassium and ammonium salts are soluble. All nitrates are soluble. Chlorides are soluble except silver and lead. Sulfates are soluble except barium, calcium and lead. Carbonates and hydroxides are insoluble except sodium, potassium and ammonium.
(Total for Question 8 = 3 marks)
-
(4)Explain
A student mixes barium nitrate solution with sodium sulfate solution and a white solid appears. Explain which substance the solid is and why the other product stays in solution.
(Total for Question 9 = 4 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 12 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain Solubility Rules and Proton Transfer to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Svante Arrhenius over three rounds, marked against descriptors you can read first.
Completely free. No subscriptions, no paywalls, no account needed to start.
Back to the lesson
- Solubility Rules and Proton Transfer — Which salts dissolve, and the broader definition of an acid that explains why ammonia counts.
- All of Incandio Chemistry · Incandio Exam Practice