Name ______________________________________________ Date _________ Period ______
Making Ionic Compounds
Purpose
After reading the lab, create your own purpose below:
______________________________________________________________________________
______________________________________________________________________________
Pre-Lab Discussion (Do not copy in your lab book)
Elements combine to form compounds. If energy is released as the compound is formed, the
resulting product is more stable than the reacting elements. In this investigation you will react
elements to form two compounds. You will test the compounds to determine several of their
properties. Ionic compounds have properties that are different from those of other compounds.
You will decide if the products you formed are ionic compounds.
Materials
Balance
Bunsen Burner
Clay Triangle
Crucible
Crucible Tongs
Iron Ring
Magnesium Ribbon (Mg)
Ring Stand
Scissors
Conductivity tester
Pre-Lab Questions
1. Write the electron configuration of the magnesium atom.
a. Based on this configuration, will magnesium gain or lose electrons to become a
magnesium ion?
b. Write the electron configuration of the magnesium ion.
c. The magnesium ion is isoelectronic to which noble gas?
2. Repeat question 1 for oxygen and nitrogen.
Procedure
1. On the balance, measure the mass of just the crucible and record this
as “a” in the Data section.
Figure A
2. Rip a 12 cm length of magnesium ribbon into 1 cm pieces. Place the
pieces in the crucible and measure the mass of the crucible and its
contents on the balance. Record as “b” in the Data section.
3. Cover the crucible and place it in a clay triangle on a ring stand
(Figure A). Heat over the burner for 2 minutes.
4. Using crucible tongs, carefully tilt the cover slightly to provide an
opening for air to enter the crucible. When the reaction starts, record
observations in the Data section. Heat the partially covered crucible
strongly for 10 minutes after the reaction starts.
5. Remove the cover and examine the contents. If any unreacted magnesium remains,
replace the cover at a slight tilt, and reheat the crucible strongly until it is all reacted.
6. Turn off the burner, re-cover the crucible using the tongs, and allow the contents to cool.
Record observations of the new compound as “d” in the Data section.
7. On the balance, measure the combined mass of the crucible and the new oxide. Record as
“c” in the Data section.
8. Place the dry solid product in a small beaker for further testing.
9. Add 10 mL of distilled water the product in the beaker and stir. Check for conductivity
and record your results.
Clean up
1. Dispose of product in the garbage.
2. Wash and dry crucible and beaker and return to front table.
Data (Create a table and remember a title)
a. Mass of Empty Crucible:
_____________________________g
b. Mass of Crucible and Unreacted Magnesium:
_____________________________g
c. Mass of Crucible and magnesium products:
_____________________________g
d. Observations Before/During/After reaction:
Analysis and Conclusions
1. Calculate the mass of the magnesium ribbon and the mass of the magnesium product.
Show your work.
2. What kind of energy was released by the reaction? What can you conclude about the
product of the reaction?
3. How do you know that magnesium metal reacts with certain components of the air?
4. Magnesium reacts with both oxygen and nitrogen from the air at the high
temperature of the crucible. Predict the chemical formulas for both products. Write
the names of these twocompounds.
5. The product formed from magnesium and oxygen is white, and the product formed
from magnesium and nitrogen is yellow. From your observations, which compound
makes up most of the product?
6. Use the result of the conductivity test to determine whether the products are ionic or
covalent. Explain.
7. If the magnesium lost mass instead of gaining mass, what could be a possible source or
error?
Real-World Chemistry
1. The magnesium ion plays an important role in aperson's biochemistry. Research the
role of this electrolyte in your physical and mental health. Is magnesium listed as a
component in a multi-vita- min and mineral tablet?
2. Research the use of Mg(OH)2 in everyday products. What is Mg(OH)2 commonly called
in over the counter drugs?