Transition elements are metals that tend to be hard and strong, and they have high melting points and boiling points. State two additional properties that are typical of transition elements but not of all metals.
Vanadium(V) oxide, V$_2$O$_5$, acts as a catalyst in the Contact process. State how a catalyst speeds up a chemical reaction.
State the operating conditions used in the Contact process.
Vanadium(V) oxide is reduced to vanadium when it is heated with aluminium. Complete the equation for this reaction. $3\text{V}_2\text{O}_5 + \ldots\text{Al} \rightarrow \ldots\text{V} + \ldots\text{Al}_2\text{O}_3$
A fuel cell produces electricity when hydrogen and oxygen react at platinum electrodes. Name the industrial process used to separate oxygen from air.
The reaction at one electrode in the fuel cell is shown. $\text{O}_2 + 2\text{H}_2\text{O} + 4e^- \rightarrow 4\text{OH}^-$ State whether this is an oxidation or reduction reaction. Explain your answer.