Stoichiometry

In the bomb calorimeter one of the combustion reactions studied is that of carbon burning in pure oxygen. The reaction in the presence of an adequate oxygen supply is:
C + O₂ Þ CO₂ . When the quantities of the elements present just satisfies this equation the reaction is a stoichiometric reaction. In practice, more oxygen is required than that indicated by the equation as the kinetics of oxygen delivery to the carbon is important in determining the actual reaction products. The reaction is also influenced by the dilution of the reactants by the combustion products. When there is a sub-stoichiometric quantity of oxygen present, the reaction will produce both CO and CO₂ , their concentrations being determined by the component balance of the equation:

C + aO₂ Þ bCO + dCO₂ .