R1.1 Measuring enthalpy changes
14 revision questions with answers for R1.1 Measuring enthalpy changes, marked SL. Read them here, or play the set as a class game on the projector. Free to host, and students join with a code.
Reaction that transfers heat to the surroundings?
- Endothermic
- ExothermicRight answer
- Isothermal
- Adiabatic
What this set covers
Measuring enthalpy changes: exothermic and endothermic reactions, energy profiles, standard conditions, activation energy, and calorimetry using q = mcΔT to turn a temperature rise into ΔH per mole.
- Common mix-up
- Students often forget the sign and per-mole step: a release of heat means ΔH is negative, and the heat in joules must be divided by the amount reacting.
- Revision tip
- Redo the calorimetry questions in three labelled steps: calculate q, convert to kJ, divide by moles, then add the sign last.
All 14 questions and answers
Reaction that transfers heat to the surroundings?
Answer: Exothermic
Energetic classification of photosynthesis?
Answer: Endothermic
Sign of ΔH for a reaction that absorbs heat from the surroundings?
Answer: Positive
During an endothermic reaction in solution, the temperature of the solution…?
Answer: Decreases
Standard pressure for thermodynamic data?
Answer: 100 kPa
Temperature usually quoted for standard enthalpy changes?
Answer: 298 K
On the energy profile of an exothermic reaction, the products lie…?
Answer: Below the reactants
Minimum energy colliding particles need to react?
Answer: Activation energy
Equation for the heat absorbed by water in calorimetry?
Answer: q = mcΔT
Specific heat capacity of water?
Answer: 4.18 J g⁻¹ K⁻¹
Heat to warm 100 g of water by 10 K (c = 4.18 J g⁻¹ K⁻¹)?
Answer: 4.18 kJ
50 cm³ of aqueous solution warms by 2.0 K; heat released (c = 4.18 J g⁻¹ K⁻¹)?
Answer: 418 J
ΔH when 0.10 mol of reactant releases 5.0 kJ of heat?
Answer: −50 kJ mol⁻¹
Main source of error making measured ΔH less exothermic in simple calorimetry?
Answer: Heat loss
Play it as a class game
Play this set opens it in splycr, where you can host it for your class straight away. Hosting needs no account: put the room code on the projector, and students join from a phone with the code and their first name. Each question plays as multiple choice, and the three wrong options were written for that question.