CAIE A Level Chemistry 9701 · Chemical energetics
A student studies the entropy changes in three processes.
Process 1: Sublimation of solid carbon dioxide at room temperature:
Process 2: Heating liquid water from 25°C to 80°C.
Process 3: Decomposition of ammonium nitrate:
(a) Define the term entropy, .
(b) For each process, describe whether the entropy change is positive or negative, and explain your reasoning.
7 marks, so the mark scheme is looking for about 7 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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