Chemistry 5070 · O Level · Exothermic and endothermic reactions

Exothermic and endothermic reactions — practice question

The energy profile shows a chemical reaction taking place both in the presence of a catalyst and in its absence. What is the enthalpy change for the catalysed reaction?

  • A$-125\,\text{kJ mol}^{-1}$
  • B$-50\,\text{kJ mol}^{-1}$
  • C$+75\,\text{kJ mol}^{-1}$
  • D$+100\,\text{kJ mol}^{-1}$

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