Question

Study the following reaction carefully. What classification should this reaction have? 4Al + 3O 2 2Al 2 O 3

Answer 1

The reaction is a synthesis…

`4Al + 3O_2 \longrightarrow 2Al_2O_3\\`

… because two substances are combining to make one other substance.

`4\stackrel{\hbox{0}}{\hbox{Al}} + 3\stackrel{\hbox{0}}{\hbox{O}}_2 \longrightarrow 2\stackrel{\hbox{+3}}{\hbox{Al}}_2\stackrel{\hbox{-2}}{\hbox{O}}_3\\`

It is also a reduction-oxidation reaction because the oxidation number of Al increases from 0 to +3 and the oxidation number of O decreases from 0 to -2.