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Practice · Chemistry · 2025 syllabus · R1.1

IB Chemistry R1.1 Measuring enthalpy changes: practice questions

8 exam-style questions on R1.1 Measuring enthalpy changes, SL and HL: 4 multiple choice, 2 data-based and 2 structured. Each one comes with the mark scheme, a model answer and the reasoning behind every mark. Free with your email.

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R1.1-01 · Paper 1A style · multiple choice · 1 mark

Reading an endothermic change

Ammonium nitrate dissolves in water: NH4NO3(s) → NH4+(aq) + NO3−(aq), ΔH = +26 kJ mol−1. Which row describes this change? [1]

  1. Exothermic; temperature of the water rises; products more stable
  2. Endothermic; temperature of the water falls; reactants more stable
  3. Endothermic; temperature of the water rises; products more stable
  4. Exothermic; temperature of the water falls; reactants more stable
Show the answer and the reasoning

Answer: B. B is correct. A positive ΔH means the system takes in energy from the surroundings, here the water, so its temperature falls. The products are higher in enthalpy, so the reactants are more stable. A and D read +26 as exothermic. C gets the sign right but then has the temperature rising, a half-true row.

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The 8 questions in R1.1

  1. R1.1-01 Reading an endothermic changePaper 1A style · multiple choice · 1 mark
  2. R1.1-02 Enthalpy of combustion from calorimetryPaper 1A style · multiple choice · 1 mark
  3. R1.1-03 Which changes release energyPaper 1A style · multiple choice · 1 mark
  4. R1.1-04 Values from an energy profilePaper 1A style · multiple choice · 1 mark
  5. R1.1-05 Identifying a metal by heat capacityPaper 1B style · data-based · 7 marks
  6. R1.1-06 Thermometric titrationPaper 1B style · data-based · 7 marks
  7. R1.1-07 Temperature rise of a neutralizationPaper 2 style · structured question · 5 marks
  8. R1.1-08 Bonds in an exothermic combustionPaper 2 style · structured question · 3 marks

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Every Biology and Chemistry question here is original, written for practice in the style of the papers set since the 2025 syllabus, with invented data. Developed independently from the International Baccalaureate Organization, which has not endorsed it. Found a mistake? Email vytis@limeadmissions.com with the question id.