CAIE A Level Chemistry 9701 · Electrochemistry
Vanadium(V) oxide reacts with calcium at high temperature to form vanadium and calcium oxide.
Describe this reaction in terms of electron transfer and changes in oxidation number. State the oxidation number of vanadium in , identify the oxidising agent and the reducing agent, and describe how the changes in oxidation number can be used to balance the equation.
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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