Writing a Lab Report for
Chem 113
Rachel Chupik and Jason Denny
General Information
• Have a title page
– Name, date, section, experiment
•
•
•
•
•
Use size 12 font in a standard font type
Make heading clearly visible
TYPE everything
Must be your original work
ASK your TA questions when in doubt
The Abstract (0.9)
• Three main components
– Chemical principles
– Experiment synopsis
– Success criteria
!!! Third person,
passive voice !!!
This experiment will test and exercise the principles of acidbase titration and determination of equivalence, as well as exercises
on the determination of the pKa of a weak acid. Through the use of
the known reactivity of a base (NaOH), an acid of unknown reactivity
and measured mass will be reacted to determine equivalence, and
equivalent weight, and by recording changes in pH, these data can
be used to determine the pKa. Success will be determined by
comparing the resulting pKa with the table of pKa values listed at the
back of the text with a reasonable result being within 10% of any
listed value.
Experimental (2)
•
•
•
•
•
•
Balanced chemical equations
Mathematical equations
Reagent table
Materials list
Diagram
Procedure
Equations (0.8)
• Chemical equations
• Mathematical equations
– Typed
– Balanced
– Include phases
– Typed
– One equation for each
type of calculation
performed
• Example from Exp 17:
• Example:
Mg (s) + 1/2 O2 (g)
MgO (s)
% 𝑀𝑀 =
% RSD =
𝑚𝑚𝑚𝑚 𝑀𝑀
𝑚𝑚𝑚𝑚 𝑀𝑀𝑀
𝑆𝑆
𝑎𝑎𝑎
x 100
x 100
Reagent Table (0.3)
• Include any chemical reactant you used
• Make table with at least the name, formula
and molar mass
• Write diatomics as diatomics
• List molecular weight to at least 2 decimal
places
Symbol
H2SO4
NaOH
C20H14O4
Common Name
Sulfuric acid
Sodium hydroxide
Phenolphthalein
Molecular Weight
(g.mol-1)
98.079
39.9969
318.33
Materials List (0.3) and Diagram (0.2)
• Materials List
– All equipment and glassware used in the
experiment
– NO chemicals
• Diagram
– Computer generated or copied from online source
– Referenced
Procedure (0.4)
• Simple, concise, stepwise outline of what YOU did
• Example:
!!! Third person, past
tense, passive voice !!!
– 1. A 0.2567 gram portion of the unknown acid was
weighed and added to the beaker, along with 50 mL of
water
and
1
drop
of
phenophthalein.
– 2. Standardized sodium hydroxide (NaOH) was titrated
into the solution, the changes in pH were recorded,
more data points were recorded, smaller volumes
were added, as the rate of change increased.
Results/Data Tables (2)
• N3….No Naked Numbers
– Always include units
• Make the table visually appealing
– Make sure a word is not split over two lines
• Include raw data and calculated numbers
Emission
Color
Scale
Reading
Wavelength
(nm)
Energy (J)
Energy
Level
Purple
180
350
1.2
5
Blue
170
450
1.5
4
Green
160
550
1.8
3
Yellow
150
650
1.9
2
Calculations (1.5)
• BAD example
– 43/7=6.1
• AWESOME example
• Include units throughout and highlight final
answer
– Again make it visually appealing
Graph (0.5)
Helium Spectrum: Scale Reading vs. Wavelength
8
7
y = 1.1429x - 0.3333
R² = 0.9796
Scale Reading
6
5
4
3
2
1
0
0
1
2
3
4
Wavelength (nm)
5
6
7
Discussion
• There is not a minimum length but it should
not exceed 2 pages
• MUST have three sections
– Chemical concept (1)
– Experimental observations (1)
– Results (1)
– Understanding of material (1)
Conclusions
• MUST include 3 things and only needs to be a
single paragraph
– Results (0.3)
– Statistics (% error) (0.5)
• Compare to literature value if possible
– Sources of error (0.2)
• Human error doesn’t count