Synthesis of Magnesium Oxide
Honors Chemistry
Introduction:
In this lab, your lab group will be responsible for reacting a specific mass of magnesium with the oxygen in the air to synthesize
magnesium oxide. Then you will determine the % magnesium found in the magnesium oxide produced. We will analyze the precision of
our technique as well as the accuracy of our technique.
For your lab:
Discuss the law of constant composition and the atomic theory and explain how this experiment sets out to confirm that these chemical
principles are true. Then, discuss why magnesium reacts with oxygen and what the product magnesium oxide is used for. Then connect to
what we are trying to demonstrate by doing this lab!
Hypothesis:
If… what are we reacting
Then… what should be the expected percentage of magnesium in magnesium oxide? (we’ll calculate this together in class)
Because…show your math!!!
Methods:
Follow the directions provided at your lab bench to burn and purify magnesium oxide. We will leave our samples to dry overnight.
Note: It is extremely important to:
1) weigh the mass of your magnesium before the lab.
2) note the mass of your crucible and cover after drying…you will not be able to take your magnesium oxide out of your crucible.
3) work carefully!!! if you break your crucible or cover…you will need to start over!
As you document your procedure for your lab, make sure to not only indicate the variable you tested and the data collected; but the
important procedural controls!!!
Data and Analysis:
Organize the data to collect into a table:
Mass of magnesium
Mass of crucible and cover after drying
Mass of crucible and cover with Magnesium oxide
Mass of magnesium oxide
Individual Analysis (trend for individual results):
1) Calculate the actual % of magnesium in the magnesium oxide product:
Mass of magnesium/mass of magnesium oxide produced
2) Compare to the expected percentage of magnesium oxide:
(actual-expected)/expected X 100%
Graph and analysis of class data:
1) Upload your class data onto Excel spreadsheet.
2) You will design a graph to analyze the relationship between starting mass and amount of magnesium oxide produced.
3) You will use that graph to figure out how much magnesium would be required to make a specific amount of magnesium oxide.
4) You need to discuss what the graph shows in the trend for your graph.
5) Use the graphing skills that you have practiced in your density lab and your isotope lab!!!
Conclusions:
Guiding questions to help you write your 3 part conclusion:

Explain whether or not you accept or reject your hypothesis based on your data. Then connect to the law of constant
composition based on the class data.

Discuss experimental error. Explain why your results were above or below the expected value. You must connect to specific
places in the procedure and how that may have threw your numbers off.

Discuss this reaction in terms of the theme of conservation of matter and energy. Explain how matter was conserved and the
role energy played in this reaction.

Can you find another example of a synthesis reaction? Research and describe the reaction, the product produced and some of
the limitations.
Bibliography:
Where did you get your information on the law of constant composition and explanation of the role of magnesium oxide as well as
another synthesis reaction?