Prepare a chemistry lab report about burning a peanut.

Burning a Peanut Data Sheet

Mass of Aluminum can (g)________13.60____________

Mass of Al can plus 50 mL water (g)______62.55_______

Mass of 50 mL of water added (g) _______48.95_______

Mass of cork plus needle (g)_________6.33___________

Mass of cork plus needle plus peanut (g)______7.41____

Mass of peanut before the burn (g)_______1.08_______

Mass of cork/needle/burned peanut (g)_____6.45______

Mass of peanut after the burn (g)_________0.12_______

Change in mass of peanut (before burn -after burn) (g)___0.96__

Starting temperature of water (to 0.1 C)_____25.2_____

Final temperature of water (to 0.1 C)_________82.4____

Δt_finalChange in temperature of water (to 0.1 C)_____57.2__

Calculations

ΔE = s_water X m_water X Δt_final + s_Aluminum x m_Aluminum x Δt_final

ΔE = (4.184J/g C) X m_water X Δt_final + (0.900J/g C) x m_Aluminum x Δt_final

ΔE from the above result is divided by the change in the mass of the peanut. The units are J/g.

Compare your result with the results on a jar of peanuts, which are:

(166 Cal./28.35 g)(1000 cal./1 Cal.)(4.184 J/1 cal.) = 24,500 J/g

Your results are expected to be lower due to heat losses. If you got 12,500J/g, it is (12,500/24,500)*100%= 51.0% of the jar value. It may be low because some heat flowed around the can and the soot meant it was not burned completely as it would be in pure Oxygen. A bomb calorimeter is sealed and uses pure Oxygen. A bomb calorimeter was used to get the jar value.

Laboratory Write-up

In addition to the Lab Report Format found in the course syllabus, make sure you have included the following items:

Headings for each section, Title, Purpose, Procedure, etc.

Amounts of reactants and products from the Data Sheet

Units properly labeled

Typed observations in the Procedure section

% Yield: your results in J/g divided by the jar value in J/g times 100%

Explanation of % yield

Degrees C should be read to 0.1 C

Weight of peanut after burn should be included

Calculations done properly

Reports are turned in for each individual even though you worked as partners. Identical reports from different people are not accepted. Identical report students will get a zero.

Lab Report Format (Make sure you write the words "Title", "Purpose", etc. in your lab report)

• Title

• Purpose

Include a brief summary (a paragraph or less) of the purpose of the experiment.

• Procedure

Include a reference to the procedure you have been given as well as a brief summary of what you did. The summary need only consist of the general methods used, and should not include specific details from the experimental procedure. Any changes or deviations from the procedure should be noted here.

• Results

This section is where you will report your analyzed data and results. It may consist of graphs or tables as well as a summary (in words) of what you have found.

• Conclusions

Explain what conclusions you can draw from your results. This is the part of the report where you tell the reader what your results mean. Any unexpected results should be discussed as well as possible reasons for why you did not get what you expected.