Evaporation of 1 quart of perspiration releases about ______ kilocalories of heat energy from the body.

The evaporation of perspiration is a process that significantly aids in the regulation of body temperature. Each gram of sweat that evaporates can dissipate heat energy, which is crucial for maintaining a stable body temperature during physical activity or in hot environments.

1. Heat Energy Release from Evaporation: It is a commonly known fact that the evaporation of water releases approximately 580 kilocalories of heat energy per kilogram.

2. Converting Quarts to Grams:

   • 1 quart of water is approximately 0.946 liters.
   • The density of water is approximately 1 gram per cubic centimeter, which means 1 liter of water weighs about 1000 grams. Thus, 1 quart of water weighs: $0.946 \, \text{liters} \times 1000 \, \text{grams/liter} \approx 946 \, \text{grams}$

3. Calculating Heat Energy:

   • Since 1 kilogram is 1000 grams, we need to calculate the heat released from 946 grams of perspiration: $\text{Heat Released} = \left( \frac{580 \, \text{kcal}}{1000 \, \text{g}} \right) \times 946 \, \text{g} \approx 549.68 \, \text{kcal}$

Final Answer

Evaporation of 1 quart of perspiration releases approximately 550 kilocalories of heat energy from the body.