A food chemist is testing out a new calorimetry device that measures the caloric value of their company’s peanut butter popcorn. It does this by combusting the food and measuring the heat transfer to a reservoir of water. Important values: cwater = 4186 J/kg*oC; ρwaer = 1.00 g/mL; Lsteam = 2.26 x 106 J/kg; Tv = 100oC; 1 cal = 4.186 J If the reservoir of water contains 15.00 L of water at 20oC, what would be its temperature after absorbing the energy from combusting 0.250 kg of simple carbohydrates? Assume that the energy contribution from combusting a simple carbohydrate is 4.00 kilocalories/gram and that there is no loss. Next, the chemist uses this device to measure the heat contribution from 0.454 kg (one 1 lb. package) of the peanut butter popcorn. Using 30.00 L of water, cooled now to 10oC, the final temperature of the water is 97.0oC after burning the popcorn. What is the caloric value of the package of popcorn (1 food calorie = 1 kilocalorie of energy? If the reservoir had only 5 L of water at 10oC, would the same combustion with the popcorn form some steam? Justify your answer mathematically
Energy transfer
The flow of energy from one region to another region is referred to as energy transfer. Since energy is quantitative; it must be transferred to a body or a material to work or to heat the system.
Molar Specific Heat
Heat capacity is the amount of heat energy absorbed or released by a chemical substance per the change in temperature of that substance. The change in heat is also called enthalpy. The SI unit of heat capacity is Joules per Kelvin, which is (J K-1)
Thermal Properties of Matter
Thermal energy is described as one of the form of heat energy which flows from one body of higher temperature to the other with the lower temperature when these two bodies are placed in contact to each other. Heat is described as the form of energy which is transferred between the two systems or in between the systems and their surrounding by the virtue of difference in temperature. Calorimetry is that branch of science which helps in measuring the changes which are taking place in the heat energy of a given body.
A food chemist is testing out a new calorimetry device that measures the caloric value of their company’s peanut butter popcorn. It does this by combusting the food and measuring the
Important values:
cwater = 4186 J/kg*oC; ρwaer = 1.00 g/mL; Lsteam = 2.26 x 106 J/kg; Tv = 100oC; 1 cal = 4.186 J
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If the reservoir of water contains 15.00 L of water at 20oC, what would be its temperature after absorbing the energy from combusting 0.250 kg of simple carbohydrates? Assume that the energy contribution from combusting a simple carbohydrate is 4.00 kilocalories/gram and that there is no loss.
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Next, the chemist uses this device to measure the heat contribution from 0.454 kg (one 1 lb. package) of the peanut butter popcorn. Using 30.00 L of water, cooled now to 10oC, the final temperature of the water is 97.0oC after burning the popcorn. What is the caloric value of the package of popcorn (1 food calorie = 1 kilocalorie of energy?
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If the reservoir had only 5 L of water at 10oC, would the same combustion with the popcorn form some steam? Justify your answer mathematically
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