CHEM 141 Grossmont College Calorimetry Lab Report
Lab Report:
Purpose:
The purpose of the Calorimetry experiment is to introduce you to application of thermochemistry. The purpose of writing the full lab report for Calorimetry experiment is to prepare you to write technical papers for journals, grants for funding, and learn to communicate scientific information to peers and the general public.
Skills:
In this lab report, you will:
Knowledge:
This assignment will also help you to become familiar with the following important content information:
Calorimetry
Tasks:
This exercise asks you to collect, organize, analyze, and evaluate data you collected in the lab. You will type a lab report that includes the following:
IntroductionGive the logic of the experiment.Be sure to define key terms and all applied experimental equations (e.g. calorimetry, calorimeter, enthalpy of formation, heat capacity of calorimeter, heat, balanced chemical equations, Hess’ law, and percent error.).Procedure ReferenceIf there are any changes to the published procedure be sure to note them here.Results and Calculations sectionTable summarizingYour major experimental data (e.g. heat capacity of calorimeter, experimental heat of formation for Mg2+ & MgO, actual heat of formation for Mg2+ & MgO, and percent error)Be sure to include the PDF with the data that you were provided when you turn in your report. GraphsSince data was given to you, you can use the graphs that were provided. You do not need to make graphs. Just paste them into the appropriate section of the report.
DiscussionWe did not record the boiling and freezing point of water experimentally. But issues with these measurements could possibly be something that would cause error in this experiment. Perhaps something related to this would provide one of your sources of error?State the heat of formation for MgO and describe any errors that may have led to an incorrect value of either the heat of formation (Mg2+ or MgO) or the calorimeter constant.ConclusionReiterate the major experimental data.
Your report will also include:
prelabbe sure to look over the comments from your instructor and correct any mistakes
experimental observationsquantitative observations (aka numerical data)qualitative observations running log Example – Calorimetry
The following data was obtained in a Calormetry
experiment similar to yours. What is the calorimeter
constant?
Data
Mass of cold water
49.731 g
Temperature of cold water
21.43 °C
Mass of warm water
49.468 g
Temperature of warm water
52.47 °C
Temperature at mixing
35.02 °C
Specific heat of water
4.184 J/g °C
Example – Calorimetry – Spreadsheet Calculations
Temperature of warm water = 52.47 °C
Temperature at mixing = 35.02 °C
Temperature change – hot water
52.47 °C – 35.02 °C = 17.45 °C
Mass of warm water = 49.468 g
Heat lost by hot water
q = mcΔT
qhot = mwarmcwaterΔTwarm
qhot = (49.468 g)(4.184 J/g °C)(17.45 °C)
qhot = 3611.69854 J
Example – Calorimetry – Spreadsheet Calculations
Temperature of cold water = 21.43 °C
Temperature at mixing = 35.02 °C
Temperature change – cold water and calorimeter
35.02 °C – 21.43 °C = 13.59 °C
Mass of cold water = 49.731 g
Heat gained by cold water
q = mcΔT
qcold = mcoldcwaterΔTcold
qcold = (49.731 g)(4.184 J/g °C)(13.59 °C)
qcold = 2827.2732509 J
Example – Calorimetry – Spreadsheet Calculations
qhot = 3611.69854 J
qcold = 2827.2732509 J
Heat gained by calorimeter
-qout = qin
qwarm = qcold + qcalorimeter
qcalorimeter = qwarm – qcold
qcalorimeter = 3611.69854 J – 2827.2732509 J
qcalorimeter = 783.9657454 J
Example – Calorimetry – Spreadsheet Calculations
qcalorimeter = 783.9657454 J
ΔTcold = 13.59 °C
Heat capacity of calorimeter
qcalorimeter = Ccalorimeter ΔTcold
𝑞𝑐𝑎𝑙𝑜𝑟𝑖𝑚𝑒𝑡𝑒𝑟
𝐶𝑐𝑎𝑙𝑜𝑟𝑖𝑚𝑒𝑡𝑒𝑟 =
∆𝑇𝑐𝑜𝑙𝑑
783.9657454 J
𝐶𝑐𝑎𝑙𝑜𝑟𝑖𝑚𝑒𝑡𝑒𝑟 =
13.59 ℃
𝐶𝑐𝑎𝑙𝑜𝑟𝑖𝑚𝑒𝑡𝑒𝑟 = 57.68695698 J/℃
𝐶𝑐𝑎𝑙𝑜𝑟𝑖𝑚𝑒𝑡𝑒𝑟 = 57.7 J/℃
Example – Calorimetry
The following data was obtained in a Calormetry
experiment similar to yours. What is the heat of
reaction for magnesium reacting with hydrochloric
acid?
Data
Volume HCl solution
100.0 mL
Temperature of HCl solution
16.92 °C
Mass of magnesium
0.5126 g
Temperature of HCl/Mg solution after mixing
39.80 °C
Density of HCl solution
1.01 g/mL
Specific heat of HCl solution
4.07 J/g °C
Example – Calorimetry – Spreadsheet Calculations
Volume of HCl = 100.0 mL
Density of HCl = 1.01 g/mL
Mass HCl solution
𝑔
100.0 𝑚𝐿 × 1.01
= 101 𝑔
𝑚𝐿
Temperature HCl solution = 16.92 °C
Temperature HCl/Mg solution after mixing = 39.80 °C
Increase in temperature on mixing
39.80 °C – 16.92 °C = 22.88 °C
Example – Calorimetry – Spreadsheet Calculations
Heat absorbed by calorimeter
q = C ΔT
q = (57.7 J/ °C)(22.88 °C)
q = 1320.176 J = 1.320176 × 103 J
Specific heat HCl solution = 4.07 J/g °C
Heat absorbed by HCl solution
q = mcΔT
q = (101 g)(4.07 J/g °C)(22.88 °C)
q = 9405.2816 J = 9.4052816 × 103 J
q of reaction
qrxn = -(qcalorimeter + q HCl solution)
qrxn = – (1.320176 × 103 J + 9.4052816 × 103 J)
qrxn = -10.7254576 × 103 J
Example – Calorimetry – Spreadsheet Calculations
q of reaction = -10.7254576 × 103 J
Mass of Mg = 0.5126 g
𝑞
Heat of reaction, 𝑚
𝑀𝑔
𝑞
−10.7254576 × 103 J
𝐽
=
= 20923.63948
𝑚𝑀𝑔
0.5126 𝑔
𝑔
moles Mg
1 𝑚𝑜𝑙 𝑀𝑔
0.5126 𝑔 𝑀𝑔 ×
= 0.021091178 𝑚𝑜𝑙
24.304 𝑔 𝑀𝑔
Molar heat of reaction, 𝑛
𝑞
𝑀𝑔
𝑞
𝑛𝑀𝑔
−10.7254576 × 103 J
𝐽
=
= −508529.0064
0.021091178𝑚𝑜𝑙
𝑚𝑜𝑙
𝑞
𝐽
1 𝑘𝐽
= −508529.0064
×
𝑛𝑀𝑔
𝑚𝑜𝑙 1000 𝐽
𝑞
𝑘𝐽
= −508.5
𝑛𝑀𝑔
𝑚𝑜𝑙
Part A
Step 2: Mass of Dry Calorimeter (g)
Step 2: Mass of Calorimeter + Tap water (g)
o
Step 3: Temperature of hot water ( C)
Step 3: Mass 250 mL beaker + 50 mL water (g)
Step 6: Mass of wet 250 mL beaker (g)
Trial 1
Trial 2
Trial 3
20.5511
69.107
69.2877 70.4226
53.2
50.1
51.7
159.4507 166.8563 164.2262
110.6936 117.7459 114.4174
Part A Trial 1
38
36
Temperature (oC)
34
32
30
28
26
24
22
20
0
100
200
300
400
500
600
700
800
900
1000
Time (s)
Part A Trial 2
36
34
Temperature (oC)
32
30
28
26
24
22
20
0
100
200
300
400
Time (s)
500
600
700
800
Part A Trial 3
36
34
Temperature (oC)
32
30
28
26
24
22
20
0
100
200
300
400
Time (s)
500
600
700
Part B
Reaction of Mg with HCl
Volume of 1 M HCl added (mL)
Mass of Mg (g)
Trial 1
99.8
0.5025
Trial 2
99.1
0.5059
Reaction of MgO with HCl
Volume of 1 M HCl added (mL)
Mass of MgO (g)
Trial 1
99.5
0.8065
Trial 2
98.5
0.8165
Mg(s) reacts with HCl(aq) Trial 1
50
Temperature (oC)
45
40
35
30
25
20
0
100
200
300
400
500
600
700
800
Time (s)
Mg(s) reacts with HCl (aq) Trial 2
50
Temperature (oC)
45
40
35
30
25
20
0
100
200
300
400
500
Time (s)
600
700
800
900
MgO(s) reacts with HCl (aq) Trial 1
32
Temperature (oC)
30
28
26
24
22
20
0
200
400
600
800
1000
1200
Time (s)
MgO(s) reacts with HCl (aq) Trial 2
29
28
Temperature (oC)
27
26
25
24
23
22
21
20
0
200
400
600
800
Time (s)
1000
1200
1400
900
1000
1400
1400
4/4/2021
2.20 Lab Report: Experiment 10: Calorimetry (GRADED ASSIGNMENT)
Criteria
Lab Notebook:
Format, Observations, Data
Formal Report:
Title Page, Objective, Introduction, Procedure Reference, Results and Calculations, Discussion, Conclusion
Spreadsheet
Excel Spreadsheet
Ratings
Pts
15 pts
60 pts
25 pts
Total Points: 100
https://gcccd.instructure.com/courses/37408/assignments/789238?module_item_id=1679116
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