Calculate the amount of air required to completely burn 1 kg of Octane (C8H18). If the amount of air is increased by 25%, calculate the equivalence ratio and the gravimetric analysis of the products.

If one mole of air/fuel mixture (rigid diatomic gas) is initially at 20◦C, is compressed and expanded 7-fold as part of the Otto cycle, and 4 kJ of heat is generated by burning the air/fuel mixture, calculate: (i) the temperature after each stage of the Otto cycle; (ii) the heat absorbed/expelled during each stage of the cycle; and (iii) the efficiency of the Otto cycle.

9. Adiabatic Flame Temperature is achieved when (a) the combustion heat is the maximum (c) the combustion heat is the minimum (b) there is no loss in the heat to the surroundings (d) all products are at the same temperature has the most affinity to water to form sulfuric acid. (b) SO₂ (d) SO 10. Among all sulfur compounds, (a) SO3 (c) SO4² 11. When comparing the performance of SI engines, the (a) Indicated -efficiency is used as the measure. (b) Thermal (d) volumetric (c) mechanical 12. For a complete combustion, the reaction time should be longer than the physical time. (a) True (b) False

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2 PARTS ( A& B) solve carefully and Explain your reasoning Gaseous ethane C2H6 is burned at constant pressure P = 1atm. The reagents enter the reaction at 25°C, and the products are at 727°C. Determine the heat released by the system for ethane combustion with (a) the theoretical stechiometric amount of oxygen (b) the theoretical amount of air (air contains 3.76 kmol of nitrogen per 1 kmol of oxygen). In which case is the heat released by the system larger? Explain why.