Nanoparticles Lab Report Evaluation Form- 50pts
1. Title Page – 2pts
- Informative title for lab report
- Name, course and lab section, date, lab instructor’s name and name of lab partner
2. Abstract – 4pts
- Brief description of experiment, results and main conclusions in under 200 words
3. Introduction – 10pts
- Purpose for the experiment described in the report
- Brief background description on nanotechnology (applications) and nanoparticles (physical and
chemical properties, size & unique optical properties
- Review of chemical concepts & techniques relevant to the experiment (importance of positive
control & one independent variable, synthesis of gold nanoparticles, using a spec, using
wavelength to determine GNP size
- Hypothesis for the experiment
4. Experimental Method – 8pts
- Lab procedures are outlined in paragraph form - no bullets!
- Experiment is well-designed
- No results or data are reported in this section
- Cite lab manual
5. Results – 8pts
- All raw data from experiment is presented in a table or graph, as appropriate
- Tables/figures are clear and easy to interpret with labeled axes and columns and units clearly
- Graphs/tables are numbered with a meaningful title and legend explaining what should be seen
by the reader (trends in data)
- All calculations from the data are included with 1 sample calculation shown with full
explanation of all variables
- No methods or discussion of the data are presented in the Results section
- Summary of the Results in text format concludes the section
6. Discussion – 11pts
- Begin with the purpose of the experiment and a statement of the hypothesis
- Did your experiment support your hypothesis? Explain why your data did (or did not) support
your hypothesis use specific data in support of each conclusion
- Correct interpretation of experimental results (what do your results indicate?)
- Discussion of possible errors that may have affected results; ways to prevent errors in the
Potential improvements or suggestions for additional experimentation?
7. Format – 4 pts
- Individual sections are labeled
- Sentence format with passive voice (no first person!) and correct verb tense are used
- Carefully proofread for grammatical & spelling errors
8. References Cited – 2 pts
- All information from other sources is cited using ACS format (Please no Wikipedia!
- Cite lab manual and at least 2 additional sources
9. Self-Evaluation – 1 pt
- Use a copy of this rubric to self-evaluate your lab report. In other words, if you were grading
your lab report, how many points would it earn?
Self-Evaluation (50 pts possible): _______
TOTAL POINTS (50 pts possible): _______
How to Write a Good Chemistry Lab Report
A good chemistry lab report follows a very specific format with separate sections in the
following order: Abstract, Introduction, Experimental Methods, Results, Discussion, and
References Cited. Each section should begin with the name of the section such as Introduction,
followed by the text of the Introduction. These sections should follow one another in sequence
but there’s no need to start a new page for each section. Your lab report must be typed and
carefully proofread for grammatical and spelling errors.
In science, what matters most in an experiment is what was done, not who did it. As a
result, the active voice should not be used in your lab report--such as “I placed the
chromatogram in the chromatography beaker for 45 minutes.” Avoid any ‘I’ or ‘we’ statements.
Instead, use the passive voice which your English teachers always told you to avoid, such as “The
chromatogram was placed in the beaker for 45 minutes”. Write the Experimental Methods and
Results sections in the past tense. In contrast, the interpretation of the data in the Discussion
section should be written in the present tense. All equations should be written on a separate
line and numbered sequentially starting at the beginning of the lab report as shown below. Be
sure to explain all variables in the equation when the equation is first introduced.
e = mc2
where e = energy
m = mass of the object
c = speed of light (3.0 X 108 m/sec)
Here’s a brief description of the different sections of the lab report and what they
should (and should not) include. Your lab instructor will give you some additional instructions.
The evaluation form your TA will use to grade your lab report is posted on Blackboard, and I
strongly encourage you to read it over before and after you write your lab report. For your first
lab report of the semester, you can get some feedback from your TA BEFORE you hand the lab
report in for grading. Just ask.
Title Page The title page should have an informative title so that the reader knows
what your experiment is about. For example, “Nitrogen Content of Water” tells the reader very
little compared to “Monthly Changes in Nitrogen Content of the Potomac River near Power
Plants”. Also include on the title page your name, the date, course name & lab section number
and your lab instructor’s name. If you worked with a lab partner, that information should also
be on the title page.
Abstract The abstract is a concise summary of your report which tells the reader what
to expect if they read the full lab report. It should name (but not describe)the general methods
used (e.g., chromatography), and give a brief description of your results and major conclusions.
Abstracts should be no longer than 1-2 paragraphs.
Introduction The main question addressed in this section is “What is this experiment
all about and why was it done?” Here you should include the purpose for the experiment, the
theory behind the major methods used in your experiment (e.g., how does chromatography
work?), pertinent equations (e.g., Beer’s law for spec lab) and any background information
which is needed to understand your experiment. “A good introduction is a clear statement of
the problem or project and why you are studying it.” (ACS Style Guide, American Chemical
Society, Washington, D.C. 1986) Every Introduction should end with a hypothesis for the
Introduction - Writing a Hypothesis A hypothesis is a statement that gives an educated
guess as to the outcome of an experiment. A good hypothesis clearly identifies the independent
and dependent variables in the experiment and is as informative as possible about the
experiment. The most common type of hypothesis is the null hypothesis because null
hypotheses are always used when the data is to be analyzed statistically. Statistical analyses
test the idea that two or more sets of data are identical and that any differences seen between
the data sets are just due to random variation. Only when the variation exceeds a set threshold
are the data sets said to be significantly different from each other. Because of the way
statistical analyses work, a null hypothesis is used for all statistical tests.
Null hypotheses are always some version of “There is no difference between the data
sets”. For example, let’s say that you were synthesizing gold nanoparticles (which you will be
doing later this semester) to see if the temperature of the synthesis reaction changes the size of
the resulting gold nanoparticles. Here are some examples of hypotheses for the described
experiment. Which hypotheses are correct and which could use some improvement? See page
4 for the answers.
1. There are no differences in the size of gold nanoparticles synthesized at
2. The size of the gold nanoparticles are all the same at different temperatures.
3. Temperature does not affect the size of nanoparticles.
4. Gold nanoparticles synthesized at lower temperatures (20oC – 50oC) are larger
compared to nanoparticles synthesized at higher temperatures.
In General Chemistry lab, statistical tests are rather rare because the size of the data set
is usually small. As a result, a null hypothesis is not necessarily required for most General
Chemistry lab experiments but it is still an acceptable option. Here’s another acceptable way to
word a good hypothesis. Let’s suppose that you are testing to see if where a student sits in the
classroom affects the grade they get in the course. A good null hypothesis for the experiment
would be “The grade which students receive in a course is not affected by where they sit in the
classroom.” An alternative and equally good hypothesis might be “Students who sit at the front
of the room receive significantly higher grades than students who sit at the back of the room.”
Experimental Method (Often called Materials & Methods in Biology lab reports) this
section answers the question “How exactly was this experiment done?” It should provide
sufficient detail for the experiment to be repeated very precisely by the reader including: the
make & model of any specialized equipment, sizes of beakers, solution volumes and
concentrations, etc… If you followed a protocol of the written lab experiment with no
modifications, summarize the protocol in a few sentences then cite the lab experiment and the
relevant pages for the procedures. If you made any changes to the lab procedure, cite the lab
experiment and indicate the specific changes you made to the procedure. No data or discussion
of the data should be included in this section.
Results Include all the raw data from the experiment in this section even if some of the
data appear inconsistent or in error. Never discard data to make the results look better. Lab
reports are evaluated not on how perfect your data is, but how well you explain your data. Be
sure to present your data in the Results section so that the reader can easily interpret your
tables and graphs and know what they mean.
Tables are usually best for presenting raw data while graphs are a good way to
summarize data from a table so that the reader can see any trends in the data. All tables and
graphs should be numbered sequentially from the beginning of the lab report and have: a
meaningful title; labeled rows, columns and axes with units; and a legend explaining what is
seen in the table or graph. Graphs should be done in Excel or an equivalent graphing program
and any statistical programs used to analyze the data should be cited in the References section.
See ‘How to Create a Graph in Excel” which is posted on Blackboard. Trend lines on graphs
should include the equation for the line on the graph. A sample calculation should be presented
in the Results section for each type of calculations but any similar additional calculations can be
presented in a table. At the end of the Results section, include a 1-3 sentence summary of the
section in text format.
Discussion This is the most important section of the Lab Report because it accepts or
rejects your hypothesis, interprets the meaning of the data and draws conclusions. In chemistry
lab reports, the discussion section should show an understanding of the chemistry behind the
procedure if explanation is needed. For example, compare the statements “The pH decreased”
versus “The pH of the solution decreased due to the release of hydrogen ions by the reaction of
. . . “ The latter connects the result of a decreasing pH with the chemistry – what good
chemistry lab reports always do. Always cite your data to support your conclusions and refer to
the data very specifically. For example, “The Rf values were about the same” isn’t nearly as
convincing as “The Rf value for the yellow dye 5 standard was 0.68 which was nearly identical to
the Rf value for the unknown dye of 0.67.”
Your data can also be compared to results from the literature. Any inconsistencies with
the literature should be thoroughly explained if possible. In addition, any errors or confounding
factors in your experiment which may have affected your results should be discussed. This
could be a random error such as you dropped the test tube and spilled half of its contents, or a
more systematic error such as the oven was set to the incorrect temperature. Predict how the
error would be expected to affect your results. Remember the lab report will not be graded on
how perfectly you did the experiment, but on how thoroughly and accurately you present and
explain the results of your own experiment. Finally, if you have any suggestions for changes or
modifications to the procedure which might improve future experiments, mention these in the
References Cited You should use the reference guidelines from the American Chemical
Society. Here are a couple of links which describe the ACS style:
Here is an example of how to cite the Chemistry 110 lab experiments that are posted on
Ferguson, J. 2017. “What’s the Best Antacid?”,
=designer&content_id=_3753950_1&course_id=_161710_1. Accessed 17 Oct 2017.
Plagiarism in Lab Reports One of the most grievous errors in chemistry lab reports is
plagiarism. All instances of plagiarism will be referred to the Dean and may result in an ‘F’ in the
class. Examples of plagiarism include copying from the lab experimental write-up, using
another student’s lab report, failure to cite online references that you paraphrased, and the use
of graphs or figures from another student’s lab report. Every student must write their own,
original lab report. While it is perfectly okay to discuss your experiment and its interpretation
with your lab partner, do not share your lab report with them or ask to see theirs.
Answers to Writing a Hypothesis:
1. CORRECT. This is a well-written null hypothesis that specifies the independent and the
dependent variables. The only way it could be more complete is to include the specific
temperatures that were tested.
2. NEEDS IMPROVEMENT. This is NOT a good null hypothesis because it is too vague,
omitting any mention that it was the temperature of the synthesis reaction that was
tested. It sounds as if the experiment was moving gold nanoparticles to different
temperatures to see if they changed size.
3. NEEDS IMPROVEMENT. This is another poor null hypothesis because it doesn’t clearly
define that it is the temperature of the synthesis reaction that is being tested.
4. CORRECT. This is a well-written alternative hypothesis that clearly identifies the
independent and dependent variables and the expected outcome of the experiment.
Synthesis and Characterization of Gold Nanoparticles
Figure 1. Size scale for nanoparticles as compared to other
materials (top). Nanoparticles can be adapted to include
biomolecules, drugs, or targeting and imaging molecules to form
nanotechnology-based drug delivery platforms (bottom).
Introduction Nanoscience and nanotechnology are the science, engineering and technology of
working with extremely small things in the range of 1 to 100 nanometers (nm) (6). One nanometer is a
very small unit because it takes 109 nanometers to make one meter and 25,400,000 nm to make one
inch. Richard Feynman is often credited as being the father of nanotechnology because of a speech he
gave in 1959 entitled “There’s Plenty of Room at the Bottom”. Feynman speculated about the ability to
visualize and manipulate individual atoms and molecules which seemed pretty crazy at the time.
Although it took another twenty plus years, the development of the scanning tunneling microscope and
atomic force microscope made it possible to not
only see individual atoms but also to move them
around. Figure 2 shows you the first creation
What’s so special about nanotechnology?
It’s not just that the particles are extremely small
such as individual atoms but more that extremely
small particles less than 100 nm in diameter, have
Figure 2. The first created nanostructure
which spelled IBM in 35 xenon atoms on a
unique properties compared to their larger
copper substrate. http://www.nano.gov/nanotechcounterparts. For example, metallic nanoparticles
may have a lower melting point, a higher surface
area per unit of volume or mass, special optical properties, unique mechanical strengths and/or
magnetic properties that their bulk metal counterparts lack. These unique physical and chemical
properties of the nanoparticles are often highly desirable for industrial and medical applications.
If I asked you what color gold atoms
were, you would probably say “gold or
yellow” because you’re thinking of gold
jewelry or a gold watch, right? While a
large sample of gold always appears gold
or yellow, a solution of gold nanoparticles
(GNPs) may appear blue, red, or purple
depending on the size of the
nanoparticles in the solution (1). Why do
gold nanoparticles appear these different
colors? When gold nanoparticles are
similar in size to a wavelength of visible
light (400–750 nm), they interact with the
light in interesting ways. The volume and
shape of the nanoparticles in a solution
determine the color of the solution. Look
at Figure 3. As the diameter of a gold
nanoparticle increases, the
wavelength of maximum
absorbance gradually shifts to
longer wavelengths in the visible
Figure 3. The size of the gold nanoparticles in
solution determines the wavelength of maximum
absorbance and their color. From Ref. 4 LizMarzán , L.M. ( 2006 ) Langmuir , 22: 32 – 41 .
These unique properties of
nanoparticles are one of the
fundamental attractions in working
with them and have been for
centuries – even before anyone had
heard the word nanoparticle.
Nanotechnology is evident in many
old churches. Although medieval
artisans were unaware that they
were using nanotechnology, the
ruby red color used in stained glass
Figure 4. Stained glass rosace in the Cathedrale Notrewindows during the Middle Ages
Dame de Chartres (France), color changes depend on
was an early application of
the size and shape of gold and silver nanoparticle.
nanotechnology (Figure 4). Modern
chemical studies have shown that these vivid colors resulted from the different sizes and shapes of the
gold and silver nanoparticles in the windows. Today, nanomaterials can not only be efficiently
synthesized but also modified with various chemical functional groups and/or conjugated with
antibodies, ligands or drugs of interest. These modified gold nanoparticles have yielded new potential
applications in biotechnology, magnetic separation, targeted drug delivery, improved diagnostic imaging
and use as vehicles for gene and drug delivery to cells.
Synthesis of Gold Nanoparticles Today you
will be synthesizing gold nanoparticles. Each
nanoparticle contains hundreds to thousands of
atoms. Unlike small molecules that have a specific
chemical formula, nanoparticles vary in the number
and arrangement of their atoms - even in a
supposedly pure batch. In order to make
nanoparticles, two general methods are commonly
used. The first is the breakdown (top-down)
method in which an external force is applied to a
solid that breaks it into smaller particles. The second
is the build-up (bottom-up) method that produces
nanoparticles starting with atoms of gas or liquid
which then undergo atomic transformations or
molecular condensations (Figure 5).
The synthesis of nanoparticles using the
microwave for heating has become a popular option
in recent year ...
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