Empirical Formula Experimental Report Sheet
Download and save this document to your computer, or print this document to complete by
hand. Complete each section of this experimental report sheet as you progress through the
online laboratory experiment. Save your answers as your complete the document. Upload your
saved document (once completed) to the submission page for this laboratory experiment.
1. Pre-Laboratory Preparation
First watch the online pre-lab videos before proceeding with this lab.
2. Data Collection
Complete the questions and table below as you watch the experimental procedure video:
A. What is used to prevent the loss of product in this lab? (2 points)
B. Record the data collected while viewing the experimental procedure video: (6 points)
C. What was used to heat the magnesium metal and initiate the reaction? (2 points)
D. Explain why the weight of the dish, lid, and contents is heavier after the reaction occurs?
(5 points)
E. A student performing the same experiment does not periodically check on the reaction,
and instead stops heating the dish after it begins to glow orange. The student weighs the
dish and finds it is lighter than expected. Provide a plausible reason why the dish is
lighter than was expected? (5 points)
Answer: You emply a lid and a stainless steel dish
Answer: Bunsen Burner
Answer: The magnesium oxide made the dish, lid and everything else heavier. A new
compound was created when the oxygen entered the chamber.
Answer: I think the dish wll become lighter because the experiment was stopped too
soon so the reaction couldn’t happen.
Material(s) Measured Weight (g)
Dish and Lid 36.469
Dish and Lid and Magnesium Metal 36.953
Dish and Lid and Magnesium Oxide 37.263
3. Data Analysis
Use the data table above and the concepts from the pre-lab videos to answer the following
analysis questions. You must show your work to earn credit for these problems.
A. How many grams of magnesium metal were used in the experiment? (5 points)
B. How many grams of magnesium oxide were produced in the experiment? (5 points)
C. How many grams of oxygen are present in the magnesium oxide sample? (5 points)
D. The molar mass of magnesium (Mg) is 24.31 g/mol. How many moles of magnesium
were used in the experiment? (5 points)
E. The molar mass of oxygen (O) is 16.00 g/mol. How many moles of oxygen were present
in the magnesium oxide compound at the end of the experiment? (5 points)
Answer: Magnesium metal weighing 36.953-36.469= 0.484g
Answer: 37.263-36=0.794 g of magnesium oxide
Answer: Magnesium oxide sample has 0.794-0.484=0.31g of oxygen
Answer: 24.31/0.484=23.826=23.826 moles
Answer: 0.31/16.00=0.019375=0.02 mol
F. What is the simplest whole-number ratio of moles of magnesium (Mg) to oxygen (O) in
the magnesium oxide compound? (5 points)
G. Based on your calculated ration in part F above, what is the empirical formula of the
magnesium oxide compound in this lab? (5 points)
4. Post-Lab
Answer each question fully. For any numerical answer, you must show your work to earn
credit, and your final answer should be reported in proper significant figures and units.
A. Why would a student encounter calculation issues if the mass of the dish and the lid was
not measured separately before measuring the mass of any other contents? (7.5 points)
B. If a lid was not used, should you expect the mass of the container and its contents to be
heavier or lighter than the expected value? Justify your answer. (7.5 points)
Answer: magnesium to oxygen is 1:1 ratio
Answer: MgO
Answer: The student would have a hard time subtracting the mass of the dish and lid
to get what he needed.
Answer: The mass of the container will be lower because the experiment wasn’t
followed through properly
C. If some of the magnesium did not react during the heating procedure, would the mass
of the container and its contents be heavier or lighter than the expected value? Justify
your answer. (10 points)
Use the following information to answer parts D – G:
In another experiment, a student reacts 0.46 g of sodium (Na) with oxygen in the air, and
finds that the final weight of the sodium oxide is 0.62 g. The molar mass of sodium (Na)
is 22.99 g/mol, and the molar mass of oxygen (O) is 16.00 g/mol.
D. How many grams of oxygen are present in the sodium oxide compound? (5 points)
E. How many moles of sodium (Na) are in the sodium oxide compound? (5 points)
F. How many moles of oxygen (O) are in the sodium oxide compound? (5 points)
G. What is the empirical formula of sodium oxide? (5 points)
Answer: The mass of the container and its contents would be lighter because it
wouldn’t be completely formed and executed properly.
Answer: 0.62-0.46=0.6g of 0
Answer: 0.46 of Na/ 22.99g/mol= 0.02 mol
Answer: 0.16 of O/16.00g/mol of O=0.01 mol
Answer: Na2O
