Final answer:
To find the grams of sucrose that would produce 2546 kcal, first calculate the energy produced per gram of sucrose (3.924 kcal/g), then divide 2546 kcal by the energy per gram to get 648.85 g. The nearest answer choice is 649.4 g (Option A).
Step-by-step explanation:
The question asks how many grams of sucrose would produce 2546 kcal if the given reaction (combustion of sucrose) releases 1342 kcal for an unspecified amount of sucrose. To solve this, we'll use the energy release information provided in the question to find out how much energy is produced per gram of sucrose and then calculate the amount of sucrose needed to produce 2546 kcal.
The reaction provided is:
C₁₂H₂₂O₁₁ + 12O₂ → 12CO₂ + 11H₂O + 1342 kcal
First step: Determine the energy produced per gram of sucrose.
Sucrose has a molar mass of 342 g/mol.
So, 342 g of sucrose produces 1342 kcal.
Therefore, 1 g of sucrose produces 1342 kcal / 342 g = 3.924 kcal/g.
Second step: Calculate the grams of sucrose needed to produce 2546 kcal.
Grams of sucrose = 2546 kcal / (3.924 kcal/g) = 648.85 g
The closest answer to 648.85 g we have in the options is 649.4 g, so the correct answer is A) 649.4 g.