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Chapter 16 Notes II. Calorimetry. What is calorimetry?. Essentially, the science of measuring heat change. Using the specific heat of something you know to find the specific heat of something you don’t. What is calorimetry?. It takes advantage of the law of conservation of energy.
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Chapter 16 Notes II Calorimetry
What is calorimetry? • Essentially, the science of measuring heat change. • Using the specific heat of something you know to find the specific heat of something you don’t.
What is calorimetry? • It takes advantage of the law of conservation of energy. • The principal shows that heat lost by one substance has to equal heat gained by another.
50g heat lost by object is 50g also heat gained by water When a hot object is put into cool water what happens? Object at 100oC Final temperature of both is 22oC Water at 20oC 250g
NOTICE: Heat lost is equal to heat gained, but temperature lost does NOT equal temperature gained
So, to find the specific heat of the object… • Solve q=mCDT for heat gained by water THEN • Use q you found to solve q=mCDT for the specific heat of the object.
Calorimeters • A calorimeter is a device that measures heat change. • It can be extremely sophisticated, or as simple as two foam cups, a thermometer and water!
Practice Problem #1 • What is the specific heat of a metal if a 50.8g sample at 100.0oC raises the temperature of 258.2g of water from 25.2oC to 28.1oC?
Practice Problem #2 • What is the specific heat of a substance if a 22.6g sample at 104.5oC raises the temperature of 125.3g of water from 22.6oC to 33.1oC?