Where the marks actually go
Across the two theory papers and the practical unit, the biggest single mark pot is formulae, equations and amounts of substance, the mole calculations that turn up inside titration questions, combustion questions and empirical formula questions. Acid-base titrations and halogen chemistry are the next two largest topics, then energetics and qualitative tests. If you only have time to drill four topics before the exam, drill those: together they carry roughly a third of the total marks.
The examiner reports for this subject point to the same handful of habits costing marks every year: incomplete observations, missing signs on enthalpy values, mechanisms with arrows that do not start in the right place, and calculations that lose marks to rounding rather than to wrong chemistry. None of that is about knowing more content. It is about how you write the answer down.
Paper structure and timing
AS 1 (Basic Concepts in Physical and Inorganic Chemistry) and AS 2 (Further Physical and Inorganic Chemistry and Organic Chemistry) are both 90 minutes for 90 marks, so work to a minute a mark. Section A on each paper is ten multiple choice questions worth one mark each. Budget ten minutes there and move on rather than agonising over one option. That leaves about 80 minutes for Section B's structured questions, including one 6-mark extended response marked for quality of written communication (QWC). Read the QWC question first so you know which parts of your later working need full sentences rather than shorthand.
AS 3 is split into two booklets sat back to back. Booklet A is the hands-on practical: 75 minutes for 25 marks across three tasks, including titration. There is no benefit to finishing early here. The marks sit in clean, consistent data, not in speed. Booklet B is the practical theory paper, 75 minutes for 55 marks across five structured questions, so roughly 15 minutes each if you split evenly, more for the questions carrying more marks.
Where the technique pays off
Structured short-answer and calculation questions carry the largest share of marks across both theory papers, with practical observation and method questions close behind. Three habits move a grade boundary faster than extra content revision.
- State the sign. Every enthalpy change needs a sign. An exothermic reaction is negative. Write the minus sign the moment you decide the reaction is exothermic, before you round anything, because the final answer line is marked on the sign as well as the number.
- Name what you see, not just that you saw it. 'A precipitate forms' is not a complete observation. State the colour and the word precipitate together, for example 'a white precipitate forms'. When two layers form during an extraction, say so and say which layer carries the colour.
- Draw curly arrows from something, not from nowhere. Every curly arrow in a mechanism starts at a lone pair or the centre of a bond and finishes on an atom or a new bond position. An arrow drawn from open space earns nothing even when the rest of the mechanism is correct.
CCEA conventions to know
Each theory paper carries one 6-mark question marked for quality of written communication. CCEA marks these against a banded mark scheme, so you need to hit enough of the indicative content points to reach the top band, not just write neatly. For this subject that usually means naming the specific intermolecular forces or bonding types involved and comparing their relative strength, rather than describing each in isolation.
State symbols matter whenever a question asks for them explicitly, particularly in ionisation energy and precipitation equations. Ionisation energy definitions specifically need the words 'one mole of gaseous atoms' or 'gaseous ions' stated, not implied.
The week before
Redo every past titration calculation you can find, working to the requested number of significant figures and rounding only at the final line. Rebuild a Maxwell-Boltzmann curve from memory at two temperatures, checking it starts at the origin and crosses the lower-temperature curve exactly once. Write out the full method for preparing a standard solution, including inverting the volumetric flask after adding the washings, since that single step accounts for lost marks every year. On the day, read both Section B QWC questions before you start writing so you know in advance which answers need full sentences.