2014 Real Exam Question: Regarding the complete combustion process using natural gas as fuel in a heater, which of the following statements is correct?
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3. Regarding the complete combustion process using natural gas as fuel for a heating furnace, which of the following statements is correct? (A) The mass of the exhaust gases is equal to the mass of the fuel burned. (B) The number of moles of the exhaust gases is equal to the number of moles of the fuel burned. (C) The mass of the exhaust gases is greater than the mass of the fuel burned. (D) The mass of the exhaust gases is less than the mass of the fuel burned. Why is the answer C? Thank you, expert!
The mass of the flue gas is the mass of the product, while the mass of the reactants should be the mass of the fuel and oxygen. The objects for comparison in the options are either the product or the reactants, and naturally, the mass of the product is greater than that of one of the reactants
Although it doesn’t affect the answer to this question, does water count or not? Complete combustion refers to a specific condition in which water is in liquid form; then shouldn’t it no longer be considered water?