posted by Bruce on .
The label on a soft drink states that 11 fl. oz (325 g) provides 285 kcal. The drink is cooled to 12.0°C before it is consumed. It then reaches body temperature of 37°C. Find the net energy content of the drink. (Hint: You can treat the soft drink as being identical to water in terms of heat capacity.)
I'm not sure how 285 kcal works into solving this, or how to get started. Thank you for any help!
The 285 kcal represents chemical energy released when the contents are consumed. There is an additional transfer of energy to the drink from the body as the soft drink warms up to body temperature:
(1.00 cal/g*C)*25 C*325 g = 8.13 kcal
The net energy content of the cold drink is 285 - 8 = 278 kcal
thank you for your help!