CHM 101L M4 Fundamentals of Calorimetry Lab Report Complete

2 1. Create a spreadsheet and graph of the data from Data Table 1, plotting temperature vs. time, and use the Y intercept to find the temperature at time 0 when the two volumes of water are mixed. a. Insert graph below. b. Activities 2 and 3 Data Table 2 5g CaCl 2 10g CaCl 2 15g CaCl 2 5g NH 4 Cl 10g NH 4 Cl 15g NH 4 Cl Mass of water (g) 100 100 100 100 100 100 Mass of salt (g) 5.03 10.06 15.1 5 10.02 15.05 Moles of salt (g x mol/g) 0.045 0.089 0.14 0.045 0.090 0.14 Initial Temperature (°C) T i 30 27 31 30 29 31 Final Temperature (°C) T f 32 30 33 32 30 32 Change in Temperature (°C) ∆T = T f - T i 2 3 2 2 1 1 Heat absorbed by 836 1254 836 836 418 418 © 2016 Carolina Biological Supply Company

5 The expression (−81.3−9.50−81.3)×100 evaluates to approximately 88.31%. Therefore, the percentage error for the enthalpy of solution of Ammonium Chloride (NH4Cl) is approximately 88.31%. Activity 4 6. Based on the data and graphs for calcium chloride and ammonium chloride, determine which compound to use and what quantity of each compound will be needed to make a chemical hot pack and cold pack. Both packs should be calculated based on using 100 g (100 mL) of water. The hot pack should reach 60 °C, and the cold pack should go down to 3.0 °C from a room temperature of 25 °C. Hot Pack: Compound needed to achieve 60 °C above room temperature: CaCl2 Cold Pack: Compound needed to achieve 3.0 °C: NH4Cl 7. What were some potential sources of error in this investigation? The biggest source of error in this particular investigation is heat loss or gain from the outside 8. Suggest some ways in which the calorimeter or lab protocol could be improved to have lower percentage of errors. Maybe find a way to seal the experiment so that air cant affect the results © 2016 Carolina Biological Supply Company