Students held a six-mole strip of copper strip over a flame until a combustion began. Students were provided the balanced chemical
reaction for the combustion of copper and asked to describe the limiting
reactant.
2Cu + O2 + 2Cuo
Student Description of Limiting Reactant
Student 1 The limiting reactant is copper because all of the oxygen
combusted and the room still contained oxygen.
Student 2 The limiting reactant is oxygen because the oxygen will be
used up before the copper.
Student 3 The limiting reactant is copper because twice as much oxygen
is needed compared to oxygen.
Student 4 The limiting reactant cannot be determined because the
number of moles of oxygen was not known.
Which student correctly describes the limiting reactant?