CAIE A Level Chemistry 9701 · Chemical energetics
Ethanol burns in oxygen according to the equation
The combustion is strongly exothermic, but ethanol in an open beaker at room temperature does not ignite.
(a) Describe the energy changes that occur during this combustion, in terms of the breaking and making of chemical bonds.
(b) Describe what a reaction pathway diagram for this reaction would show, and describe why the reaction does not start at room temperature.
6 marks, so the mark scheme is looking for about 6 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
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