Micro Mole Rockets
Advanced Chemistry Lab #2
Name
Date
Purpose: ( brief statement of what you are attempting to do. These are similar to the
objectives. )
Procedure: (A brief description of the method you are using. You may refer to the lab
document for specific instructions, but you should include a brief statement of the
method. DO not include lengthy, detailed directions. A person who understands
chemistry should be able to read this section and know what you are doing. Include all
chemicals used and the major equipment. )
Pre-Lab Questions:
1. Write the balanced chemical equation for the single-replacement reaction of
zinc and hydrochloric acid to generate hydrogen gas.
2. Write the balanced chemical equation for the yeast-catalyzed decomposition
of hydrogen peroxide to generate oxygen gas and water. Note: Since a
catalyst is not really a reactant or product, it is usually written over the arrow.
Results:
Observations: (General descriptions of visible appearances or changes that occur
during the experiment, such as “table salt is a white, cube-shaped crystal which dissolves
in water. (Qualitative))
Data: (Neatly arranged measured values listed in tabular form. The units of
measurement MUST be included with the numerical values. The accuracy of the
measurement can also be included as a range (+/-). Calculated answers that are derived
by performing a simple mathematical operation can also be included in the data table. If
the graphs are included, make the graphs an appropriate size. Label all axes and give
each graph a title.)
“Pop-test” Properties of H2 Gas
“Pop-test” Properties of O2 Gas
Pop-test Porperties of O2:H2 Gas Mixtures
Oxygen: Hydrogen Mole Ratio
1:5
2:4
3:3
4:2
5:1
Relative Loudness
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Calculations: (Show all calculations with formula and appropriate units on all
numbers. Neatly demonstrate the math set-ups, including units. Label what is being
calculated. –make it organized. Show error calculations where appropriate. If
experiments are qualitative, this section may be omitted.)
Conclusion: (Make a simple statement concerning what you can conclude form the
experiment. Refer back to the purpose of the lab to write this section. (i.e. How was the
purpose of the experiment fulfilled?))
Discussion of Theory: (In this section you should include such information as: What
theory was demonstrated in this experiment (Include concepts used in the experiment)?
What do the calculations show? Why does (or doesn’t) the experiment work? This
section shows me that you understand the concepts used in the lab. Be detailed and ask if
you need help! )
Experimental Sources of Error: (What are some specific sources of error, and how do
they influence the data? Do they make the values obtained larger or smaller than they
should be? Which measurement was the least precise? Instrumental error and human
error exist in all experiments, and should not be mentioned as a source of error unless
they caused a significant fault. Significant digits and mistakes in calculations are NOT a
valid source of error. In writing this section it is sometimes helpful to ask yourself what
you would do differently if you were to repeat the experiment and wanted to obtain better
precision. If you can calculate percent error, do so and include in this section. )
Post Lab Questions: (Answer any questions included in the lab. Answer in such a way
that the meaning of the question is obvious in your answer. )
1. Draw a bar graph to illustrate the relative loudness produced by pop-testing
various oxygen/hydrogen gas mixtures.
2. Explain the relative loudness of pure oxygen and pure hydrogen in the poptest.
3. Write a balanced chemical equation for the combustion reaction of hydrogen
and oxygen to give water.
4. Complete the following sentence to describe the number of moles of each
reactant involved in the combustion of hydrogen: ________ moles of hydrogen
react with ______ moles of oxygen to give ________ moles of water.
When the reactants in a mixture are present in the exact mole ratio given by the
balanced chemical equation, all of the reactants should be used up when the
reaction is over. There will be no “leftover” reactants. However, if one of the
reactants is present in an amount greater than its mole ratio, then that reactant
cannot react completely, and some of it will be left over at the end of the reaction.
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5. Use the mole ratio of hydrogen to oxygen from Question #4 to determine
what happens when various hydrogen/oxygen gas mixtures are allowed to
burn. Complete the following table to indicate which reactant (H2 or O2) is
present in excess, and how much of it will be left over after the combustion
reaction is complete. Note: The second one has been completed as an example.
Parts H2
Parts O2
Which reactant is present in
excess?
How much of that reactant is left
over?
6
0
5
1
H2
4
2
3
3
2
4
1
5
0
6
3
6. Which oxygen/hydrogen gas mixture produced the most explosive mixture?
Explain why this mixture was most explosive.
7. Why do the hydrogen and oxygen gas mixtures in the collection bulb not
react as soon as they are collected? Note: Consider the role of the match and
the properties of gas molecules at room temperature.
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