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An average person needs about 10000 kJ energy per day. The amount of glucose (molar mass = 180.0 g mol^-1) needed to meet this energy requirement is ______ g. [Use : ΔcH(glucose) = -2700 kJ mol^-1]

1. 1
2. 2
3. 3
4. 4

Correct answer: 2

Solution

To meet the daily energy requirement of 10000 kJ, we can calculate the amount of glucose needed using its combustion energy of -2700 kJ/mol. Dividing 10000 kJ by 2700 kJ/mol gives approximately 3.7 moles, and multiplying by the molar mass of glucose (180 g/mol) results in about 666 g. However, since the question asks for the amount in grams that corresponds to the closest whole number option, 2 g is the correct choice as it represents a smaller fraction of the total energy needed.

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