All assignments must be done individually. No lab partners. Use the data and videos provided on eCourseware to answer the following questions. You must include the correct units with all your answers. Submit your final answers in the correct Dropbox before the deadline. Make sure that your final document is organized and easy to read.

Additivity of Heats of Reaction:  Hess’s Law

All assignments must be done individually. No lab partners. Use the data and videos provided on eCourseware to answer the following questions. You must include the correct units with all your answers. Submit your final answers in the correct Dropbox before the deadline. Make sure that your final document is organized and easy to read.

Data and Calculations                                          

1. Enter the data in the following table. (14 pts)

 Reaction 1Reaction 2Reaction 3
Mass of NaOH(s) added  (no solid NaOH)
Total mass of solution (assume the density of each solution is 1.00 g/mL)   
Final temperature   
Initial temperature   
Change in temperature, ΔT   

2. Enter the answers for questions 3-5 in the following table. (30 pts)

 Reaction 1Reaction 2Reaction 3
Heat, q   
ΔH   
Moles of NaOH   
ΔH/mol   
Experimental value 
Accepted value 
Percent error 

3.    (a) Calculate the heat released by each reaction, q, by using the formula:    q = Cp • m • ΔT

Where the heat capacity (Cp) is 4.18 J/g°C, m is the total mass of the (reaction) solution in grams, and the ΔT  is the change in temperature in oC. Then convert joules to kJ in your final answer. (b) Next, find ΔH (ΔH = –q ).

4.   Calculate moles of NaOH used in each reaction. In Reactions 1 and 2, this can be found from the mass of the NaOH. In Reaction 3, it can be found using the molarity, M, of the NaOH and its volume, in L.

5.   (a) Use the results from questions 3 and 4 to determine the ΔH/mol of NaOH in each of the three reactions. (b) To verify the results of the experiment, combine the heat of reaction (ΔH/mol) for Reaction 1 and Reaction 3. This sum should be similar to the heat of reaction (ΔH/mol) for Reaction 2. (c) Using the value in Reaction 2 as the accepted value and the sum of Reactions 1 and 3 as the experimental value, find the percent error for the experiment.

6. Include an image of your handwritten calculations for questions 3-5. (10 pts)

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