A-Level ChemistryYear 2017Q17
Page 08 17. Chemical reactions are in a state of dynamic equilibrium only when A the reaction involves no enthalpy change B the concentrations of reactants and products are equal C the activation energies of the forward and backward reactions are equal D the rate of the forward reaction equals that of the backward reaction. 18. Bromine and hydrogen react together to form hydrogen bromide. H2(g) + Br2(g) ↓ 2HBr(g) Bonds broken Bonds made Bond Bond enthalpy (kJ mol−1) H―H 2 × H―Br H―H 436 Br―Br Br―Br 194 H―Br 366 The enthalpy change for this reaction, in kJ mol−1, is A −102 B +102 C −264 D +264.
Paper Source:NH_Chemistry_all_2017.pdf
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Exam Specification Info
This question is part of the UK A-Level Chemistry syllabus. In the actual exam, structured questions typically require linking specific keywords to gain full marks. Applaa helps you drill these topics.
Syllabus levelAdvanced Level (A-Level)
SubjectChemistry
Official MarksVariable (2–6 marks)