Heat and Calorimetry

Lab 5: Heat and Calorimetry

Pre-lab Questions

1.  A calorie is measurement of how much energy a food contains.

2.  Have to change mL into grams.

Mass of water = density of water x volume of water

Mass of water = 1.00g/mL x 80.mL

Mass of water = 100 g

E=mc ΔT

E= 100 g x (1cal/g oC) x (7.87 oC) = 787 cal

787 cal/0.851g = 925 cal/g

925 cal/g x 1 cal/1000 cal = .925 cal/g

The cookie had .925 cal/g.

Table 2: Data for Calorimetry Experiment  Junk Food | Volume of Water (mL) | Mass of Water (g) | Mass of Junk Food (g) | Initial WaterTemperature (oC) | Maximum Temperature (oC) | Water ΔT (oC) |

Sample A: Cheetos |  80.mL |  80g |  .520 g |  30oC |   38.9oC |  8.9oC |

Sample B: Marshmallow |  80.mL |  80g |  .470 g |  24.8oC | 28.5oC | 3.7oC |

Sample C:Honey Graham Cracker |  80mL |  80g |  .500 g |  30oC | 36oC |  8oC |

Sample D:Lays BBQ Chip |  80mL |  80g |  .486 | 32oC | 39oC | 7oC |

Possible errors in measuring temp. based on no digital thermometer.Calculations1.  A. CheetosE=mc ΔTMass of water = density of water x volume of waterMass of water = 1.00g/mL x 80.mL Mass of water = 80 gE=mc ΔTE= 80 g x (1cal/g oC) x (8.90 oC) = 712 cal712 cal/0.520g = 1370 cal/g1370 cal/g x 1 cal/1000 cal = 1.370 cal/gB. MarshmallowE=mc ΔTMass of water = density of water x volume of waterMass of water = 1.00g/mL x 80.mL Mass of water = 80 gE=mc ΔTE= 80 g x (1cal/g oC) x (3.7 oC) = 296 cal 296 l/0.470g = 630 cal/g630cal/g x 1 cal/1000 cal = .630 cal/g C. Honey Graham CrackerMass of water = density of water x volume of waterMass of water = 1.00g/mL x 80.mL Mass of water = 80 gE=mc ΔTE= 80. g x (1cal/g oC) x (8oC) = 640cal640cal/0.500g = 1280 cal/g1280 cal/g x 1 cal/1000 cal = 1.280cal/g D. Lays BBQ ChipMass of water = density of water x volume of waterMass of water = 1.00g/mL x 80.mL Mass of water = 80 gE=mc ΔTE= 80 g x (1cal/goC) x (7oC) = 560 cal560 cal/0.486g = 1152. cal/g1152 cal/g x 1 cal/1000 cal = 1.152 cal/g 2.  A. Cheetos...