Chemistry 0620 · IGCSE · Exothermic and endothermic reactions

Exothermic and endothermic reactions — practice question

The equation for the breakdown of hydrogen iodide is shown below. $\text{2HI} \rightarrow \text{H}_2 + \text{I}_2$ Some bond energies are listed. H-H: $440\,\text{kJ/mol}$ I-I: $150\,\text{kJ/mol}$ H-I: $300\,\text{kJ/mol}$ What is the energy change for this reaction?

  • A$-290\,\text{kJ/mol}$
  • B$-10\,\text{kJ/mol}$
  • C$+10\,\text{kJ/mol}$
  • D$+290\,\text{kJ/mol}$

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