The candle lab: calculations

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The candle lab calculations

• Data 0.95 g, 30.6 C
• 1.
• q heat/energy change, units J or Joules
• c specific heat, units J/gC
• m mass, units g or grams
• ?T temperature change, units C
• 2. 200 g
• 3. q cm?T 4.18 J/gC x 200 g x 30.6 C
• 25 582 J or 25.6 kJ

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• 4. 25.581 kJ/0.95 g wax
• 26.9 kJ 27 kJ
• 5. First, assume the heat absorbed by the water
  is equal to the heat released by the candle
• 1 mol C25H52 352 g or 352.52
• mol 0.95 gx 1 mol / 353 g 0.00269 mol
• kJ/mol 25.581 kJ / 0.00269 mol
• 9 510 kJ/mol 9.5 x 106 J/mol
• 6. Calorimeter An apparatus used in the
  determination of the heat of a reaction
• Calorimetry The science of measuring the
  quantities of heat that are involved in a
  chemical or physical change.

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• 7. The calorimeter is made up of more than just
  water (the metal from the can)
• Other sources of error include anything that
  interferes with the transfer of heat or the
  measurement of that heat. E.g. incomplete
  transfer of heat, loss of heat, evaporation of
  water, incomplete combustion.
• Notexperimental error, inaccurate thermometer

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