Achieving theoretically complete combustion of one kg of carbon demands ______________ kg of air?
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Answer: A. 11.5
Explanation
Complete combustion of carbon requires oxygen supplied from surrounding atmospheric air streams. Stoichiometric calculations based on molecular weights dictate the exact mass of air needed. Burning one kilogram of pure carbon demands approximately eleven point five kilograms of air. Carbon reacts with oxygen to form carbon dioxide during stoichiometric combustion processes. Air contains roughly twenty-one percent oxygen and seventy-nine percent nitrogen by volume. Nitrogen acts as an inert diluent but absorbs thermal energy during the combustion reaction.
Boiler operators use stoichiometric air calculations to determine optimal combustion efficiency. Supplying exact theoretical air is difficult, so practical systems use slight excess air margins. Accurate air-fuel ratios minimize unburned carbon losses and reduce harmful stack emissions. Option B suggests half a kilogram, which provides far too little oxygen for carbon conversion. Option C proposes twenty-three kilograms, which represents double the required stoichiometric mass. Option D suggests twelve kilograms, a common approximation but less precise than eleven point five.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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