Edexcel IGCSE Chemistry · Spec 3.7C, 3.18
Bond-Energy Calculations and Reversible Heating (Paper 2)
Covers calculate enthalpy change from bond energies, Interpret the sign of the answer and Explain heating ammonium chloride.
Chemistry revision video
Bond-Energy Calculations and Reversible Heating (Paper 2)
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Spec 3.7C, 3.18
What you need to know
- Calculate enthalpy change from bond energies
- Interpret the sign of the answer
- Explain heating ammonium chloride
Active recall
Quick check
Answer each question before opening the answer.
What is the bond-energy equation?
Energy to break bonds minus energy released making bonds
What does a negative delta H mean?
The reaction is exothermic
Why does ammonium chloride appear on cooler glass?
Ammonia and hydrogen chloride recombine as they cool
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