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Subject
Chemistry
Date
Feb 20, 2024
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Experiment 4
Enthalpy of Chemical Reactions
GRADING RUBRIC
EXPERIMENT 4 – LAB REPORT Worksheet
(80 pts)
Student name: ____Paulina Uribe___
Lab partner name: ___Britney Nguyen___
TA name: ___Rose___
Day & time of the lab: _02/15_
The lab report packet for this experiment should consist of the following in THIS ORDER:
The lab report packet for this experiment should consist of the following:
1.
(10 pts)
IN-lab notebook pages
1.1. Experimental procedure
1.2. Recorded experimental values and the file name (as saved on your USB drive)
1.3. Observations if any were noted
2.
(70 pts) The WORKSHEET
3.1
(22 pts) POST-lab data analysis
3.2
(10 pts) Figures of graphs with captions in the right positions. Tables with captions
3.3
(38 pts) Complete (full sentence) answers to the discussion questions (DQ; Provide well- rounded answers composed with complete sentences for full credit. If you need to refer to any of the data or tables produced during the “Data Analysis” section, clearly indicate their location within your answers for the graders to find them readily.)
Complete this worksheet and turn in your digital lab packet to Canvas. Feel free to adjust space in this document as needed. The tables provided here are only an example of these may look like, feel free to replace the entire tables with your own creations using Excel, etc All tables and figures (graphs) must be accompanied by captions which should be positioned above tables and below figures.
TURN IN the digital copy to Canvas on the due date by 11:59 pm. All electronic material must be completed by the due date to avoid late penalties.
1
P. Sotelo SP2023
Reaction 1
Reaction 2
Reaction 3
Reaction 4
Reaction 5
Time (s)
Temperature °C
Time (s)
Temperature °C
Time (s)
Temperature °C
Time (s)
Temperature °C
Time (s)
Temperature °C
0
21.4
0
20.5
0
21.1
0
20.9
0
20.
15
21.4
15
20.5
15
20.9
15
20.8
15
20.
30
21.3
30
20.4
30
21
30
20.8
30
20.
45
21.3
45
20.4
45
21
45
20.8
45
20.
60
21.3
60
20.4
60
27.7
60
20.9
60
20.
75
21.2
75
20.5
75
33.3
75
20.7
75
20.
90
31.2
90
21.4
90
33.5
90
20.7
90
20.
105
34.6
105
21.4
105
33.4
105
20.7
105
20.
120
34.7
120
21.4
120
33.2
120
21.6
120
22.
135
34.8
135
21.4
135
33.2
135
23
135
35.
150
34.7
150
21.4
150
33
150
23.7
150
38.
165
34.6
165
21.6
165
33
165
24.4
165
38.
180
34.5
180
21.4
180
33
180
25.3
180
39.
195
26.3
195
39.
210
26.9
210
39.
225
27.9
225
3
240
28.5
240
3
255
29
255
38.
270
29.5
270
38.
285
30
285
38.
300
30.4
300
38.
315
30.5
315
38.
330
30.6
330
38.
345
30.9
345
38.
360
30.9
360
38.
375
31.1
375
38.
390
31.2
390
38.
405
31.3
405
37.
420
31.2
420
37.
435
31.1
435
37.
450
31.2
450
37.
465
31.3
465
37.
480
31.2
480
37.
0
20
40
60
80
100
120
140
160
180
200
0
5
10
15
20
25
30
35
40
Reaction 1
Time
Temperature
0
20
40
60
80
100
120
140
160
180
200
19.5
20
20.5
21
21.5
22
Reaction 2
Time
Temperture
Highest temp: 21.6°C 0
20
40
60
80
100
120
140
160
180
200
0
5
10
15
20
25
30
35
40
Reaction 3
Time
Temperature
0
100
200
300
400
500
600
0
5
10
15
20
25
30
35
Reaction 4
Time
Temperature
0
100
200
300
400
500
600
0
5
10
15
20
25
30
35
40
45
Reaction 5
Time
Temperature
Highest temp: 34.8°C Highest temp: 33.5°C Highest temp: 31.3°C Highest temp: 39.2°C 2
P. Sotelo SP2023
3
P. Sotelo SP2023
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(22 pts)
POST-LAB DATA ANALYSIS
Post-lab should contain all work done outside of the lab, especially sample calculations for
every type of math operation, as detailed in the DATA ANALYSIS in reference to DQs
. You
may choose to show your work in the post-lab notebook pages or typed in the data analysis
and discussion portions of the worksheet.
PART B: The Reaction of Hydrochloric Acid and Ammonium Hydroxide
The following steps will guide you on how to proceed with data analysis using the software of
your choice, Excel or LoggerPro:
1.
If you choose to use Excel
, open your file (.txt) from Part B in Excel. 4
P. Sotelo SP2023
a.
Open Excel and select the “data” tab.
b.
Select the “From Text” action, and select the desired file to import.
c.
Excel should automatically identify your data as “Delimited”. Ensure that this is the
selected file type and click “Finish”.
d.
Some versions of Excel will import data sets without retaining their numerical values
(your data will not be erased, but Excel will treat numbers as letters). Data cannot be
analyzed in this state. To convert the text into values, select a column, and click “Text to
Columns” under the Data tab. Numbers that are successfully converted to values will be
aligned on the right side of the cell. Generate a new graph
for each reaction.
e.
Highlight the desired data set, select “Insert” from the task bar in the top left, then select
“Insert Scatter”.
f.
From the “Design” tab, you can change the name of an axis by selecting “Add Chart
Element”, then “Axis Titles”.
g.
Ensure that each graph (three total) plots Time on the x-axis and Temperature on the
y-axis.
h.
Identify the maximum temperature value for each reaction and label it on its graph.
i.
Add an appropriate title to each graph by selecting “Add Chart Element”, then “Chart
Title”.
If you choose to use
Logger Pro 3.14,
open the (.txt or .qmbl) file saved on your USB
drive from Part B. To generate a new graph for each reaction:
Select “Insert” from the task bar in the top left, then select “
Graph
”.
o
You can change the name (and corresponding data of) an axis by simply left
-
clicking on it and selecting the desired option from the drop-down menu. To
toggle between the temperature readings from each different reaction, click on the
y-axis title (Temperature) to access the drop-down menu, then select “More” to
see options for each individual run.
o
Ensure that each graph (three total) plots Time on the x-axis and Temperature on
the y-axis.
o
Select “Analyze” and “Statistics” to add a statistics legend to each graph.
o
Add an appropriate title to each graph by right
-clicking on the graph and selecting
“Graph Options”.
o
Copy and paste all three graphs into the R&D section of the report. (2 pts/each) FIGURES (five total) Figure 1:
(insert caption below the figure)
…
5
P. Sotelo SP2023
0
20
40
60
80
100
120
140
160
180
200
0
5
10
15
20
25
30
35
40
Reaction 1
Time
Temperature
Figure 1: The reaction of Hydrochloric acid and Sodium Hydroxide had a maximum temperature
of 34.8°C at 135 seconds.
Figure 2:
…
0
20
40
60
80
100
120
140
160
180
200
19.5
20
20.5
21
21.5
22
Reaction 2
Time
Temperture
Figure 2: The reaction of Sodium Hydroxide and Ammonium Chloride had a maximum
temperature of 21.6°C at 165 seconds.
Figure 3:
…
6
P. Sotelo SP2023
Highest temp:
34.8°C
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0
20
40
60
80
100
120
140
160
180
200
0
5
10
15
20
25
30
35
40
Reaction 3
Time
Temperature
The reaction of Hydrochloric Acid and Ammonium Hydroxide had a maximum temperature of
33.5°C at 90 seconds.
Figure 4:
0
100
200
300
400
500
600
0
5
10
15
20
25
30
35
Reaction 4
Time
Temperature
The reaction of Hydrochloric Acid and Magnesium Hydroxide had a maximum temperature of
31.3°C at 405 seconds.
Figure 5:
7
P. Sotelo SP2023
Highest temp:
33.5°C Highest temp:
31.3°C
0
100
200
300
400
500
600
0
5
10
15
20
25
30
35
40
45
Reaction 5
Time
Temperature
The reaction of Hydrochloric Acid and Magnesium Metal had a maximum temperature of 39.2°C
at 180 seconds.
2.
The net ionic equations for each of the three sub-reactions performed in Part B are shown
below. Use the equation for Hess’s Law with the values in Table 5 to calculate the
“theoretical” molar enthalpy of each reaction, and record the values in Table 6.
Reaction 1:
HCl
(aq)
+ NaOH
(aq)
⟶
H
2
O
(l)
+ NaCl
(aq)
+ heat
Net: H
+
(aq)
+ OH
–
(aq)
⟶
H
2
O
(l)
+ heat
Reaction 2:
NaOH
(aq)
+ NH
4
Cl
(aq)
⟶
NH
3 (aq)
+ H
2
O
(l)
+ NaCl
(aq)
+ heat
Net:
OH
–
(aq)
+ NH
4
+
(aq)
⟶
NH
3 (aq)
+ H
2
O
(l)
+ heat
Reaction 3:
HCl
(aq)
+ NH
3 (aq)
⟶
NH
4
Cl
(aq)
+ heat
Net:
H
+
(aq)
+ NH
3 (aq)
⟶
NH
4
+
(aq)
+ heat
Table 5
: Enthalpies of formation.
Compound
Δ
H
f
°
(kJ/mol)
OH
–
(aq)
–229.99
H
+
(aq)
0
H
2
O
(l)
–285.83
NH
4
+
(aq)
–132.51
NH
3 (aq)
–80.29
Hess’s Law
: ∆ H
rxn
°
=
∑
∆ H
f
products
°
−
¿
∑
∆ H
f
reactants
°
¿
(3 pts) Table 6
: Calculated “theoretical” molar enthalpies of Reactions 1-3.
Equation/Reaction
Net Ionic Equation
Δ
H
rxn
(kJ/mol)
8
P. Sotelo SP2023
Highest temp:
39.2°C
1
H
+
(aq)
+ OH
–
(aq)
⟶
H
2
O
(l)
+ heat
-55.84 kJ/mol
2
OH
–
(aq)
+ NH
4
+
(aq)
⟶
NH
3 (aq)
+ H
2
O
(l)
+ heat
-3.62 kJ/mol
3
H
+
(aq)
+ NH
3 (aq)
⟶
NH
4
+
(aq)
+ heat
-52.22 kJ/mol
3.
(3 pts) Calculate the amount of heat energy (
q
) in kJ that was absorbed by the surroundings,
calorimeter and water, for each sub-reaction. Use 1.03 g/mL for the density of all solutions.
Use the specific heat of water, 4.184 J/(g·°C), for all solutions. The calorimeter constant is
25.5 J/°C.
Reaction 1: 6120 J
Reaction 2: 502 J
Reaction 3: 5660 J
4.
(3 pts) Calculate the enthalpy change, ∆
H
rxn
, for each sub-reaction in terms of kJ/mol.
Remember that the sign of q
from the calorimeter represents the surroundings (+) and q
from
the reaction represents the system (−).
Reaction 1: -
61.2 kJ/mol Reaction 2: -
5.02 kJ/mol
Reaction 3: -
56.6 kJ/mol
9
P. Sotelo SP2023
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5.
(2 pts) Using the ∆
H
rxn
values from Step 4 above and the balanced net ionic equations for
Reactions 1 and 2, sum Reaction 1 and Reaction 2 appropriately (to yield the same net ionic
equation as Reaction 3) to calculate the experimental molar enthalpy change for Reaction 3.
Writing out the net ionic equations will help with this step. Reaction 1 = Reaction 2 + Reaction 3
-61.2 kJ/mol = -5.02 kJ/mol -56.2 kJ/mol
6.
(2 pts) Using the “theoretical” Δ
H
rxn
values calculated in Step 2 above, sum Reaction 1 and
Reaction 2 appropriately to calculate the “theoretical” molar enthalpy change for Reaction 3
(the process for this step is analogous to that of Step 5 above).
Reaction 1 = Reaction 2 + Reaction 3
-55.34 kJ/mol = -3.62 kJ/mol -52.2 kJ/mol
10
P. Sotelo SP2023
7.
(1 pt) Determine the percent error (equation below) for the experiment using the answers
obtained in Steps 5 and 6 above. Assume that a % error ≤ 15% is a reasonable result.
7.62%
=
|
−
52.22
kJ
mol
+
56.2
kJ
mol
−
52.22
kJ
mol
|
×
100
7.62% error
PART C: The Formation of Magnesium Oxide
Part B illustrated the additivity of reaction heats by utilizing Hess’s Law. In Part C, this principle
can be applied to determine a heat of reaction that would be difficult to obtain by direct
measurement – the change in enthalpy of formation of magnesium oxide from it elements in their
standard states. This reaction is represented by the equation:
(Equation 4)
Mg
(s)
+ ½ O
2 (g)
⟶
MgO
(s)
This equation can be obtained by combining Equations 1, 2, and 3:
(Equation 1)
MgO
(s)
+ 2 HCl
(aq)
⟶
MgCl
2 (aq)
+ H
2
O
(l)
(Equation 2)
Mg
(s)
+ 2 HCl
(aq)
⟶
MgCl
2 (aq)
+ H
2 (g)
(Equation 3)
H
2 (g)
+ ½ O
2 (g)
⟶
H
2
O
(l)
The heats of reaction for Equations 1 and 2 will be determined from the experimental results. Δ
H
for Reaction 3 was not measured and is provided (–285.83 kJ). Equations 1, 2, and 3 will then be
summarized to obtain the enthalpy of formation of MgO, Equation 4.
If using Excel
to import the .txt file saved on your USB drive from Part C. Generate a
new graph for each reaction:
11
P. Sotelo SP2023
o
Highlight the desired data set, select “Insert” from the task bar in the top left, then
select “Insert Scatter”.
o
Ensure that each graph (two total) plots Time on the x-axis and Temperature on
the y-axis.
o
Identify the maximum temperature value for each reaction and label it on its
graph.
o
Add an appropriate title to each graph.
o
Copy and paste both graphs into the R&D section of the report
If using Logger Pro 3.14
, open the file saved on your USB drive from Part C. Generate a
new graph for each reaction:
o
Select “Insert” from the task bar in the top left, then select “Graph”.
o
Ensure that each graph (two total) plots Time on the x-axis and Temperature on
the y-axis.
o
Add a statistics legend to each graph.
o
Add an appropriate title to each graph.
o
Copy and paste both graphs into the R&D section of the report
Figure 4:
0
100
200
300
400
500
600
0
5
10
15
20
25
30
35
Reaction 4
Time
Temperature
The reaction of Hydrochloric Acid and Magnesium Hydroxide had a maximum temperature of
31.3°C at 405 seconds.
12
P. Sotelo SP2023
Highest temp:
31.3°C
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Figure 5:
0
100
200
300
400
500
600
0
5
10
15
20
25
30
35
40
45
Reaction 5
Time
Temperature
The reaction of Hydrochloric Acid and Magnesium Metal had a maximum temperature of 39.2°C
at 180 seconds.
8.
(2 pts) Calculate the amount of heat energy (
q
) in kJ that was absorbed by the surroundings,
calorimeter and water, for each sub-reaction. Use 1.01 g/mL for the density of the HCl
solutions. Use the specific heat of water, 4.184 J/(g·°C), for all solutions. The calorimeter
constant is 25.5 J/°C. Reaction 4: 4.66 kJ
Reaction 5: 9.96 kJ
9.
(3 pts) Calculate Δ
H
rxn
for reactions #4 & #5 with respect to MgO and Mg (kJ/mol rxn).
Record these values in Table 7. (hint: Determine ΔH and Determine the number of moles of
MgO and Mg used.)
13
P. Sotelo SP2023
Highest temp:
39.2°C
10.
(2 pts) In table 7, determine Δ
H
f
for MgO: using the ∆
H
rxn
values from Step 10 above, sum
Equations 4, 5, and 6 appropriately to calculate the experimental molar enthalpy change for
Equation 7. Δ
H
f
= –285.83 kJ for Equation 6.
Table 7
: Reaction schemes for the formation of MgO.
Equation Reaction
Δ
H
rxn
(kJ/mol)
4
MgO
(s)
+ 2 HCl
(aq)
⟶
MgCl
2 (aq)
+ H
2
O
(l)
-155
5
Mg
(s)
+ 2 HCl
(aq)
⟶
MgCl
2 (aq)
+ H
2 (g)
-498
6
H
2 (g)
+ ½ O
2 (g)
⟶
H
2
O
(l)
–285.83
7
Mg
(s)
+ ½ O
2 (g)
⟶
MgO
(s)
-628.83
155-498-285.33 = -628.83 kJ/mol
11.
(1 pt) Determine the percent error for the answer obtained in Step 11. The “theoretical” value
for Δ
H
f
is –602 kJ/mol. Assume that a % error ≤ 15% is a reasonable result.
%
error
=
|
theoretical value
−
experimental value
theoretical value
|
×
100
|
−
602
kJ
mol
+
628.83
kJ
mo
l
−
602
kJ
mol
|
×
100
=
4.46%
error
14
P. Sotelo SP2023
DISCUSSION QUESTIONS
Provide well-rounded answers composed with complete sentences for full credit.
If you need to refer to any of the data or tables produced during the “Data Analysis” section, clearly indicate their location within your answers for the graders to find them readily.
1.
(4 pts)
Briefly describe, in words, how the “theoretical” molar enthalpy was calculated for
the sub-reactions in Part B
. Include the results of these calculations for all three reactions.
The theoretical molar enthalpy was calculated in Part B by finding the ∆
H
rxn
values of the three
reactions using their respective net ionic equations and enthalpies of formation. The ∆
H
rxn
for the
first reaction is -55.84 kJ/mol and for equation 2 it is -3.62 kJ/mol. The appropriate sum of the
∆
H
rxn
from Reaction 1 and Reaction 2 should equal to the ∆
H
rxn
of Reaction 3, which is -52.22
kJ/mol according to the values on the table.
2.
(2 pts)
During the experimental procedure, were the three sub-reactions in Part B
endothermic or exothermic? How did you know that the reactions were endothermic or
exothermic?
The three sub-reactions in part B were exothermic. The initial and max temperatures of the three reactions were recorded on table 1, since the max temperatures for all three reactions were greater than the initial temperatures, there was an increase in the temperature and the system released heat.
3.
(4 pts)
Briefly describe how the amount of heat energy (
q
) absorbed by the surroundings was
calculated for the sub-reactions in Part B
. Include the results of these calculations for all
three sub-reactions.
To calculate the amount of energy absorbed by the surroundings, the equation q=mcΔT+cΔT
must be used. To calculate the mass (m) for each sub-reaction the mL of the solution (100 mL) is
multiplied by the density of the solution (1.03 g/mL), then that value is multiplied by the specific
heat of water (c) which is 4.184 J/g·°C, then the product of that is multiplied by the ΔT of the
reaction. The ΔT varies in each reaction, ΔT is found by subtracting the initial temperature of the
solution from the max temperature. Finally, mcΔT is added to the multiplication of the
calorimeter constant (second c) which is 25.5 J/·°C times the ΔT. Reaction 1 had a q value of
6120 J, reaction 2 had a q value of 502 J, and reaction 3 had a q value of 5660 J.
4.
(4 pts)
Briefly describe how the enthalpy change (Δ
H
rxn
) was calculated for the sub-reactions
in Part B
. Include the results of these calculations for all three sub-reactions.
To calculate the enthalpy change for the sub-reactions the Joules of the reaction are divided by
0.1 mol because that represents the limiting reactant, the Joules must have a negative sign since
the reaction was endothermic, then that is multiplied by the result of the division of 1 kJ by 10^3
kJ, that should equal to the enthalpy change in kJ/mol. Reaction 1 had a (Δ
H
rxn
) value of -61.2
kJ/mol, reaction 2 had a value of -5.02 kJ/mol, and reaction 3 had a value of -56.6 kJ/mol.
15
P. Sotelo SP2023
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5.
(4 pts)
Describe in detail how Reactions 1 and 2 were combined to determine the
experimental molar enthalpy change for Reaction 3 in Part B
. Include the results of this
calculation.
To determine the molar enthalpy change for reaction 3, one must remember that reaction 1=
reaction 2 + reaction 3. If the molar enthalpy change for equation 3 was not known, a simple
equation can be made using the values of reaction 1 and 2, -61.2 kJ/mol = -5.02 kJ/mol + x,
where x represents the Δ
H
rxn for reaction 3, and solving for x. x= 56.2 kJ/mol
6.
(3 pts)
The value of Δ
H
rxn
for Reaction 3 in Part B
was determined by three different
methods: (1) The “theoretical” value was determined in DQ1 , (2) the experimental value
was determined using Hess’ Law of Summation in DQ5, and (3) the value was obtained
directly by measuring the temperature change for Reaction 3 in DQ4. State these three values
of Δ
H
rxn
and compare them. Was the Δ
H
rxn
obtained in Step 5 of the Data Analysis accurate
(what was the %error)? Explain. Do the results of this experiment support Hess’s Law?
The theoretical Δ
H
rxn value for reaction 3 is -52.22 kJ/mol, the experimental Δ
H
rxn value is 56.2
kJ/mol, and the Δ
H
rxn obtained directly is -56.6 kJ/mol. The value obtained in step 5 is not totally
accurate with a percentage error of 7.62% but considering that anything <15% is a reasonable
result, this is very close. The results of the experiment do support Hess’ law because the enthalpy
change of the reaction is the approximately the same for all three values.
7.
(3 pts)
Were the reactions in Part C
endothermic or exothermic? How did you know that the
reactions were endothermic or exothermic? Why was it necessary to use two different
concentrations of HCl in the reactions?
The reactions in part C were exothermic because heat was released by the system and the
solution rapidly increased in temperature. Increasing the concentration of HCl allows for more
molecules to interact with the Mg, a higher concentration affects the reaction rate and the amount
of energy produced in a certain time frame.
8.
(6 pts)
Describe in detail
how the enthalpy of formation of magnesium oxide was determined
(
Part C
). Include all
necessary steps that were used to convert Δ
T
to Δ
H
rxn
. Describe how
Equations 4, 5, and 6 were combined to determine the experimental molar enthalpy change
for Equation 7. Include the results of these calculations by inserting Table 7
from the data
analysis here.
The enthalpy of formation of magnesium oxide was determined by adding reaction 5 and six
while subtracting reaction 4, this gave me a value of -628.83 kJ/mol
-Reaction 4+ reaction 5 + reaction 6 = reaction 7
155-498-285.33 = -628.83 kJ/mol
Table 7
: Reaction schemes for the formation of MgO.
16
P. Sotelo SP2023
Equation Reaction
Δ
H
rxn
(kJ/mol)
4
MgO
(s)
+ 2 HCl
(aq)
⟶
MgCl
2 (aq)
+ H
2
O
(l)
-155
5
Mg
(s)
+ 2 HCl
(aq)
⟶
MgCl
2 (aq)
+ H
2 (g)
-498
6
H
2 (g)
+ ½ O
2 (g)
⟶
H
2
O
(l)
–285.83
7
Mg
(s)
+ ½ O
2 (g)
⟶
MgO
(s)
-628.83
9.
(2 pts)
How did the experimental value of the change in enthalpy of formation of magnesium
oxide compare to the “theoretical” value (
Part C
)? Do the results of this experiment support
Hess’s Law? The experimental value of the change in enthalpy of formation of magnesium oxide was close to
the theoretical one with a percent error of only 4.46%. The results of the experiment do support
Hess’ law because the enthalpy values are very close to each other.
10.
(3 pts)
Define Δ
H
rxn
and Δ
H
f
. Which Part
of the experiment demonstrated the change in
enthalpy per mole of a reaction? Which Part
of the experiment demonstrated the standard
molar enthalpy of formation for a reaction?
Δ
H
rxn
is the amount of heat released or absorbed during a chemical reaction as reactants are being
converted into products, this change is determined from the balanced equation. Δ
H
f is the change
in enthalpy that occurs when one mole of a substance at standard conditions is created from its
elements in their standard states. Part B of the experiment demonstrated the change in enthalpy
per mole of reaction while Part C demonstrated the standard molar enthalpy of formation for a
reaction.
11.
(3 pts)
Discuss various observed or reasonably predictable experimental errors. What impact
did/would those errors have on your experimental data? (be specific)
There are probably many experimental errors in this lab probably primarily coming from
imprecise measurements of the solutions used, the amount of MgO and Mg was not exact, and
the temperature probe could have not measured data correctly due to stirring. These possible
experimental errors can affect our experimental data by showing an incorrect change in
temperature leading to incorrect Δ
H
rxn
and Δ
H
f
values.
17
P. Sotelo SP2023
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COLLEGE OF HEALTH SCIENCES
RESULTS AND OBSERVA TIONS:
PARTI: BENEDICTS TEST FOR REDUCING SUGARS
田
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PATIENT
COLOR
RESULT and
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Before: Blue-green
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WHITE PRECIPITATE:
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After: Greenish brown
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General Chemistry II Laboratory Manual, 2019 Revsion
39
Questions:
1) When you set up the temperature probe using Capstone, you did not calibrate it to
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Thi consistently off by 1 or 2°C. Why won't this affect your results for this experiment?
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STARTING AMOUNT
esc
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X
C
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Convert 23.4 kJ to calories
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t
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P
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J
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7
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(
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Instructions You are required to produce a short lab report using the information given in the accompanying document, ‘Lab report assessment_student data’. This document introduces an experiment, and also provides a set of experimental data for this experiment. You are required to use this data to perform steps 8 and 9 of the procedure. This includes calculations of a particular value, and then comparison to the true value. Consider any experimental errors when comparing calculated values and true values. Your report should be between 300 and 500 words (including all table contents and titles of tables and graphs). Your lab report should consist of three sections only: • Experimental • Results and Discussion • Conclusion You do NOT need to include an introduction section. Your experimental section should be written in appropriate lab report format, (passive voice, 3 rd person, in paragraphs). Your results and discussion section should contain the data presented in table format, and…
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