4) The Orsat analysis is used to analyse the dry exhaust gas from an engine which has the following percentage composition by volume: 8,85% carbon dioxide, 1,2% carbon monoxide, 6,8% oxygen and 83,15% nitrogen. The fuel supplied had a percentage composition by mass of: 84% carbon, 14% hydrogen and 2% oxygen. Determine the mass of air supplied per kg fuel burnt. 5) With the aid of a well labelled chart, explain why combustion efficiency is measured as a function of Carbon Dioxide, Carbon Monoxide and Oxygen contained in the products