In which change of state do the particles gain energy and change from a regular, closely packed arrangement to a random arrangement in which they are still touching?
← O Level subjects
O Level Chemistry5070
2 papers120 marks2 h 45 min
What we predict comes up
From the syllabus weighting and how the papers are usually set. The papers below follow it.
- Stoichiometry17%Moles, titration, limiting reactant and percentage yield calculations are the largest single block of marks.
- Electrochemistry and chemical energetics14%Electrolysis products and half-equations plus a bond energy calculation appear every series.
- The Periodic Table and metals12%Group trends, displacement, the reactivity series, the blast furnace and rust prevention are regulars.
- Organic chemistry12%Cracking, alkene tests, ethanol manufacture, esters and polymers form a full structured question.
Paper 1: Multiple Choice
1 h · 40 marks · Calculator allowed
- There are forty questions on this paper. Answer all questions.
- For each question there are four possible answers, A, B, C and D. Choose the one you consider correct.
- Each correct answer will score one mark. There is no penalty for a wrong answer.
- Relative atomic masses are given in the questions where they are needed. The volume of one mole of any gas is 24 dm³ at room temperature and pressure (r.t.p.).
- You may use a calculator.
Answer or mark a question and your score adds up here.
Answer all questions40 marks
Cotton wool soaked in concentrated aqueous ammonia is placed at one end of a long glass tube, and cotton wool soaked in concentrated hydrochloric acid at the other end. A white ring of ammonium chloride forms inside the tube. Where does the ring form, and why?
The gas in a sealed gas syringe is heated. The plunger is free to move, so the pressure stays the same. What happens?
37 more questions
Every paper, every question, the answers and the mark scheme. Free with a Knomi account.
Not included: The practical component (Paper 3 Practical Test or Paper 4 Alternative to Practical, 40 marks, 20% of the qualification) is not included; this sitting is Papers 1 and 2.