Eduqas A Level Chemistry
Eduqas A Level Chemistry PI4.1 Enthalpy Changes for Solids and Solutions Exam Questions
Free Eduqas A Level Chemistry exam questions on PI4.1 Enthalpy Changes for Solids and Solutions, with mark schemes. Covers lattice enthalpy, Born-Haber cycles, enthalpy of solution and hydration.
PI4.1 Enthalpy Changes for Solids and Solutions exam questions
1 question pack of real past exam questions with its mark scheme. Answer every question without notes, then mark your answers line by line against the mark scheme.
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A Level Chemistry Flashcards
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About Eduqas A Level Chemistry PI4.1 Enthalpy Changes for Solids and Solutions
This topic covers energy changes involving ionic solids.
What you need to know
- Lattice enthalpy Energy change when one mole of an ionic solid forms from gaseous ions.
- Born-Haber cycles Calculate lattice enthalpy from atomisation, ionisation and electron affinity data.
- Solution ΔHsol = −ΔHlatt(formation) + ΣΔHhyd.
- Factors Ionic charge and radius affect lattice and hydration enthalpies.
Common mistakes in PI4.1 Enthalpy Changes for Solids and Solutions
- Mixing up lattice formation and dissociation signs.
- Forgetting to double atomisation for diatomic elements where needed.
- Ignoring second electron affinity is endothermic.
Try three PI4.1 Enthalpy Changes for Solids and Solutions exam-style questions
1. Explain why MgO has a more exothermic lattice enthalpy than NaCl. (2 marks)
Show the mark scheme answer
Mg²⁺ and O²⁻ have higher charges (1) and smaller radii, giving stronger attraction (1).
2. Define enthalpy of hydration. (1 mark)
Show the mark scheme answer
The enthalpy change when one mole of gaseous ions dissolves to form aqueous ions.
3. State why the second electron affinity of oxygen is endothermic. (1 mark)
Show the mark scheme answer
Energy is needed to add an electron to a negative ion against repulsion.
PI4.1 Enthalpy Changes for Solids and Solutions FAQs
What does this topic cover?
Lattice enthalpy, Born-Haber cycles, solution and hydration enthalpies.
Do I need to draw Born-Haber cycles?
Yes, and calculate missing values.
Why do some salts dissolve endothermically?
Entropy increase can still make dissolving feasible.
Revise this topic with flashcards: A Level Chemistry Flashcards, with mark scheme answers for Anki and Quizlet.
