Final answer:
The energy released when 15 grams of gasoline are burned can be calculated using the enthalpy of combustion of gasoline, which is approximately 46.7 kJ/g. Multiplying this value by 15 grams results in 700.5 kilojoules of heat being released.
Step-by-step explanation:
To determine how many kilojoules of heat would be released when 15 grams of gasoline are burned, we need to know the specific enthalpy of combustion for gasoline. This value tells us how much energy is released per unit mass of the substance when it is completely burned.
According to the referenced information, the enthalpy of combustion of gasoline averages -35 kJ/g. However, there seems to be some discrepancy in the values provided, as another source indicates an enthalpy of combustion of 1.28 × 105 kJ/gal. Assuming 1 gallon is approximately 3.78541 liters and given that the density of gasoline is 0.692 g/mL, we can calculate the energy released from 15 grams.
First, we convert the energy per gallon to energy per gram:
- 1.28 × 105 kJ/gal * 1 gal/3785.41 mL * 1 mL/0.692 g = 46.7 kJ/g
Now, using the obtained value of 46.7 kJ/g, we can calculate the total energy released when 15 grams of gasoline are burned:
- 15 g * 46.7 kJ/g = 700.5 kJ
Therefore, when 15 grams of gasoline are burned, approximately 700.5 kilojoules of heat would be released.