Question 81Motor Plants - Assistant Engineer

The correct answer is D) water vapor and carbon dioxide. In a theoretical perfect combustion of diesel fuel in a diesel engine, the by-products would be water vapor (H2O) and carbon dioxide (CO2). This is because the complete oxidation of hydrocarbons in the diesel fuel results in these two compounds as the final products of the combustion reaction. The other answer choices are incorrect because: A) Aldehydes are not a typical by-product of diesel engine combustion, and carbon dioxide is correct. B) Carbon monoxide is a product of incomplete combustion, not perfect combustion. C) Nitrogen is not a product of the combustion reaction, and carbon monoxide is incorrect.