Final answer:
Approximately 47,971,216 kJ of heat is released when 998 kg of n-heptane burns completely.
Step-by-step explanation:
The heat of combustion for n-heptane (C7H16) is 4817 kJ/mol. To calculate the amount of heat released when 998 kg of n-heptane burns completely, we need to convert the mass of n-heptane to moles using its molar mass. The molar mass of n-heptane is calculated by adding up the atomic masses of its constituent elements: (7 x 12.01) + (16 x 1.01) = 100.21 g/mol. Therefore, 998 kg of n-heptane is equal to 998,000 g, which is 9955.2 moles.
To find the heat released, we can use the given heat of combustion, which is 4817 kJ/mol. We multiply this value by the number of moles of n-heptane: 4817 kJ/mol x 9955.2 mol = 47,971,216 kJ.
Therefore, when 998 kg of n-heptane burns completely, approximately 47,971,216 kJ of heat is released.