Calorimetry Post Lab (1)

Raw data Mass of each sausage Sausage I Sausage II Sausage III Mass (g) 14.041 13.257 12.574 Part I: Heat Capacity of a Human Hand Mass of Coffee cup calorimeter (g) Mass of apparatus + water (g) Mass of DI Water delivered (g) Temp of DI Water ( o C) Internal Temp of sausage ( o C) Temp of DI Water after sausage ( o C) Mass of apparatus, water + sausage (g) Trial 1 214.125 300.837 86.712 20.2 5.1 18.6 313.28 Trial 2 214.054 302.151 88.097 20.2 5.4 18.9 319.42 Part II: Heat Pack Thermodynamics Temp of DI Water ( o C) Final Temp ( o C) in Temp ( o C) △ Exothermic/ Endothermic? Anhydrous CaCl 2 20.5 27.2 + 6.7 Exothermic NaCl 22.1 20.6 - 1.5 Endothermic KNO 3 21.6 20.2 - 1.4 Endothermic Salt used: Anhydrous Calcium Chloride (CaCl 2 ) Trial 1: 60mL DI Water Mass of apparatus (g) Mass of apparatus + water (g) Mass of DI Water (g) Temperature of DI Water ( o C) Mass of salt (g) Temperature of plateau ( o C) 214.04 265.98 51.94 20.9 4.62 30.1

Trial 2: 40mL DI Water Mass of apparatus (g) Mass of apparatus + water (g) Mass of DI Water (g) Temperature of DI Water ( o C) Mass of salt (g) Temperature of plateau ( o C) 214.11 255.67 41.56 21.2 4.47 31.8 Trial 3: 20mL DI Water Mass of apparatus (g) Mass of apparatus + water (g) Mass of DI Water (g) Temperature of DI Water ( o C) Mass of salt (g) Temperature of plateau ( o C) 213.64 234.30 20.66 22.2 4.41 34.6 Sample calculations: Part I: Average mass of a Vienna Sausage: = 13.291g 14.041+ 13.257 + 12.574 3 Estimation of # of sausages it would take to have the same volume as my hand: 14 sausages ∼ Class average estimation of # of sausages it would take to have the same volume as our hands: 14.33 sausages ∼ Estimated mass of an average hand: (13.921g) (14.33 sausages) = 199.5g Standard deviation of mass (Error): = (14.041 − 13.291) 2 + (13.257 − 13.291) 2 + (12.574 − 13.291) 2 3−1 0.7

KNO 3 Endothermic Salt used in experiment: Anhydrous CaCl 2 Trial 1 (60mL): = 30.1 O C - 20.9 O C = 9.20 O C △𝑇𝑒??𝑒𝑟𝑎??𝑟𝑒 Ratio of the mass of the heat pack salt to the mass of the water = 4.62g: 51.94g Trial 2 (40mL): = 31.8 O C - 21.2 O C = 10.6 O C △𝑇𝑒??𝑒𝑟𝑎??𝑟𝑒 Ratio of the mass of the heat pack salt to the mass of the water = 4.47g: 41.56g Trial 3 (20mL) = 34.6 O C - 22.2 O C = 12.4 O C △𝑇𝑒??𝑒𝑟𝑎??𝑟𝑒 Ratio of the mass of the heat pack salt to the mass of the water = 4.41g: 20.66g Molar Enthalpy of Dissolving Salt: Data from Trial 1: x = .0416 mol CaCl 2 4.62𝑔 𝐶𝑎𝐶? 2 1 ??? 𝐶𝑎𝐶? 2 110.98𝑔 𝐶𝑎𝐶? 2 = ∆𝐻 ?𝐶∆𝑇 ? = = 5.23 x 10 4 ∆𝐻 (4.62𝑔 + 51.94𝑔) (4.184 𝐽 𝑔 ? 𝐶 )(9.20 𝑂 𝐶) .0416 ??? 𝐶𝑎𝐶? 2 𝐽 ??? Average molar enthalpy: = 4.52 x 10 4 (5.23 𝑥 10 4 ) + (5.07 𝑥 10 4 ) + (3.27 𝑥 10 4 ) 3 𝐽 ??? Standard deviation: ((5.23 𝑥 10 4 ) − (4.52 𝑥 10 4 )) + ((5.07 𝑥 10 4 ) − (4.52 𝑥 10 4 )) + ((3.27 𝑥 10 4 ) − (4.52 𝑥 10 4 )) Error estimate = 1.09 x 10 4 ± 𝐽 ???

Part III: q = m hand C hand hand ∆𝑇 q = (199.5g)( 2.9 )(22 o C) = 1.3 x 10 4 Joules 𝐽 𝑔 ? 𝐶 q = )(n) (∆𝐻 1.3 x 10 4 J = (5.23 x 10 4 )(n) 𝐽 ??? 0.25 mol = n Mass of CaCl 2 : (110.98 (0.25 mol) =28g CaCl 2 𝑔 ??? ) Since the of heat pack needs to raise the temperature of an average hand from 15°C to 37°C ∆𝑇 (+12 O C), data from the 3 rd trial will be used to calculate appropriate mass of water to use in heat pack since from 3 rd trial is closest to this. ∆𝑇 = 4.41𝑔 20.66𝑔 28 𝑥 x = 1.3 x 10 2 g H 2 O Results: Estimated mass of an average hand (grams): 199.5 0.7 ± Specific Heat Capacity of Each Sausage 𝐽 𝑔 ? 𝐶 Trial 1 3.1 Trial 2 2.7 Average specific heat capacity ( ): 2.9 0.3 𝐽 𝑔 ? 𝐶 ± Trial # Molar Enthalpy ( ) 𝐽 ???

be done using this process, a possible future experiment could include which salt would be best to use in an ice pack and lower the temperature of a human hand.