Question

Which of the following is not an endothermic reaction?

• A. Dehydrogenation
• B. Ethane to ethene
• C. Combustion of propane
• D. Change of chlorine molecule into chlorine atoms

Answer 1

Answer: (C)

Combustion of propane

Answer 2

Combustion of propane is an exothermic reaction because the enthalpy of combustion (ie, $\Delta H$ ) is always negative.