Lab Report 1- The Ice Fisherman’s Friend PDF

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Memo To: Boss Date: February 19, 2020 Subject: The Ice Fisherman’s Friend In our experiment we found that The Ice Fisherman’s Friend is technically feasible as our reaction reached a temperature greater than 95°F. By our calculations the amount of CaCl2 needed was 16.174 grams to reach 95°F. The average final temperature reached of the two trials ran was 99.77°F. This is sufficient as the target temperature for a warmed hand. In our unknown salt determination experiment we were able to determine that the unknown salt, “Salt of Luck”, was NaCl. The average heat capacity of the solid part of our calorimeter was, Cp,sol = 54.636 J/g°C. This was found by calculating the Cp,sol of each of our three trials and taking an average for the final answer. In table 1 the Cp,sol from our experiments can be found and sample calculations for determining Cp,sol are shown below.

Table 1. Values for Cp,sol

Trial 1 Trial 2 Trial 3 Average

Cp,sol (J/g°C) 48.89 53.65 61.67 (Trial 1+ Trial 2+Trial 3)/3 = 54.636

The average heat of dissolution of our unknown salt was 3.51 kJ/mol which is equivalent to 60.06 J/g. This was found by taking an average of the heat of dissolution of trials 1, 2, and 4. Trial 3 was discarded as the experiment setup was disturbed before completion. Our measured heat of dissolution 3.51 kJ/mol, compared to the given heat of dissolution of NaCl of 3.9 kJ/mol, our measured value appears to be close but a little less. Calculating the apparent percent error (calculations shown below), it can be seen that there is a 10% error in our determination.

The measure density of our sausage was 0.96625 g/mL, calculated by the equation density = m/v = 18.553g/19.2mL = 0.96625 g/mL. The average specific heat of our sausage was

4.1115 J/g°C. This was calculated by calculating the Csp,sausage of each of our two trials and taking an average for the final answer. In table 2 the Csp,sausage from our experiments can be found and sample calculations for determining Csp,sausage are shown below. Trial 1 was omitted from calculations as the stir bar was not functioning during the trial 1 experiment.

Table 2. Values for Csp,sausage

Trial 2 Trial 3 Average

Csp,sausage (J/g°C) 5.069 3.154 (Trial 1+ Trial 2)/2 = 4.1115

Calorimeter Temperature Over Time 30

Temperature (°C)

29 28 27

ΔT

26 25 24

0

1

2

3

4

5

6

7

8

Time (min)

Figure 1. Graph showing calorimeter temperature as a function of time for Trial 2 of the specific heat experiment

The estimated volume of an adult hand was measured by determining the volume of my hand to be 200 mL. The mass and volume of CaCl2 needed for reaction was determined to be 16.174 grams, calculations shown below.

The same Styrofoam cup calorimeter setup was used in each experiment, even though the cup was dried as thoroughly as possible some of the water of previous trials may have stuck to the cup and added to the amount of water. Therefore, the calculations may have underestimated the amount of water in the calorimeter. Another source of error may lie in the difficult process of evenly warming the sausage. It was hard to determine whether the sausage was uniformly warmed and when taking the temperature of the sausage there may have been measurement inaccuracies due to placing the thermometer in as warmer/colder spot on the sausage. This may have resulted in over/underestimating the sausage temperature. Doing this would change the determined ΔT of the sausage and influence the ΔHrxn calculations....