10 Comparing it CHEETOS CHIPS 550cal for 95 grams = 5.78cal/gram x 4.184KJ/cal= KJ/gram390cal for 75 grams= 5.2cal/gramx 4.184KJ/cal=21.76kJ/gram
11 We’ve been talking about Q=MC(delta)T What is Calorimetry?the technological process of measuring energy changes in a chemical systemWhat is a Calorimeter?A device used to measure the energy change of a chemical systemUsed to insulate the reaction against energy/product loss
15 Question 1: TogetherIt takes 41.8J to heat a kg chunk of gold from 10oC to 27oC. Calculate the specific heat capacity of gold.
16 Steps we followed 7. Sub in the numbers 8. Do the math – WITH UNITS! Six Steps of PreparationWhat do we need to find?What numbers do we have?What ‘hidden numbers’ do we have?What equation(s) can we use?Do we need to rearrange the equation?Do we need to convert any units?Four Steps of Action7. Sub in the numbers8. Do the math– WITH UNITS!-- WITH SIGNS! (+/-)9. Round the answer to the appropriate significant digits10. Check your answer: Does it make sense?Does it answer the question that was being asked?
17 Question 2: On your ownOn a mountaineering expedition, a climber heats water from 0oC to 50oC. Calculate the mass of water that could be warmed by the addition of 8.00kJ of heat.
18 Let’s take it one step further I took a 0.400kg block of Aluminum, and heated it on a hot plate to 212oC. I then transferred it to 0.800L of water at 23.0oC. The final temperature of the system was 41.35oC. What is the specific heat capacity of aluminum?