Question

Carbon monoxide gas reacts with elemental oxygen gas to form carbon dioxide gas. In a 1.00 L flask, 4.30 atm of carbon monoxide reacts with 2.50 atm of oxygen gas.

a) write the balanced equation for this composition reaction

b) Determine which is the limiting reactant in this composition reaction

c) How many moles of gaseous product are produced by this reaction?

Answer 1

a) CO(g) + 1/2O2(g) -----> CO2(g)

b) PV= nRT ----> n CO= 4.3atm x 1L/0.082L.atm/mol.K x T

We don´t know T, but it doesn´t matter because it will be the same for both reactants. I will assume it is 25ºC=298K

nCO= 0.176 mol

nO2= 2.5atm x 1L/0.082L.atm/mol.K x 298K= 0.102 mol

1 mol CO reacts with 1/2 mol O2, so, 0.176mol CO reacts with 0.088 mol O2. But we have 0.102mol O2, so O2 is in excess, and CO is the limiting reactant.

c) 1 mol CO produces 1 mol CO2, so, 0.176mol CO produces 0.176mol CO2.