Chemical reactions — IGCSE Sciences - Co-Ordinated (0654) questions by topic
Investigating how calcium carbonate's particle size affects its reaction rate with hydrochloric acid, describing how to measure the carbon dioxide produced, and comparing marble chips of different sizes reacting with excess acid drive the 6 chemical reactions questions from 2023 and 2024, worth 10 to 13 marks.
State, explain and calculate top the command words, with suggest and describe used for method-based questions on measuring gas volume or reaction rate. Because rate-of-reaction questions reward precise cause-and-effect reasoning about surface area, work through them here and submit for instant marking, so a confused link between particle size and surface area is corrected before it recurs.
What examiners look for
- Examiners repeatedly found candidates confusing large particle size with large surface area when selecting the fastest experiment.
- A recurring criticism is that very few candidates explained the need to check a colour change against a pH chart.
- Few candidates could clearly describe the structural difference between a liquid and a gas.
- Reports note many candidates were awarded a mark for showing a single shared pair of electrons in a bonding diagram.
May–June 2024, Paper 42
Some students investigate the reaction between marble chips and dilute hydrochloric acid. They react marble chips of three different sizes, A, B and C, with excess dilute…
Answer this question and get it marked →May–June 2024, Paper 43
Calcium carbonate reacts with hydrochloric acid. The equation for the reaction is: CaCO3 + 2HCl - CaCl2 + H2O + CO2 Describe how the volume of carbon dioxide gas produced in this…
Answer this question and get it marked →October–November 2024, Paper 42
A student investigates the reaction between calcium carbonate and dilute hydrochloric acid. The student does the experiment using three different sets of conditions, A, B and C.…
Answer this question and get it marked →October–November 2024, Paper 43
A student investigates the reaction between calcium carbonate and dilute hydrochloric acid. Fig. 5.1 shows the apparatus used (a flask of calcium carbonate and dilute hydrochloric…
Answer this question and get it marked →October–November 2023, Paper 32
A student investigates the rate of reaction between calcium carbonate and hydrochloric acid. The student does the experiment four times and each time uses the same mass of calcium…
Answer this question and get it marked →October–November 2023, Paper 42
A student investigates the reaction between large marble chips and excess dilute hydrochloric acid. Fig. 8.1 shows the apparatus (gas collected over water in a measuring cylinder;…
Answer this question and get it marked →Other IGCSE Sciences - Co-Ordinated topics
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