Experiment Two: Properties of Inorganic Compounds and Metathesis
Reactions
Objectives
You will be able to study the properties of inorganic compounds by performing simple chemical
reactions in test tubes. Observations of chemical reactions such as formation of precipitates,
evolving of gases and changes in colors will be recorded and translated to chemical equations.
Introduction
This experiment serves several goals, among which it helps the student to:
1. Observe physical appearance of common inorganic chemicals.
2. Recognize chemical changes.
3. Determine solubility of salts by studying metathesis reactions.
In this experiment simple chemical reactions will be performed in test tubes and the relation
between chemical formulas and physical appearances will be established. Additionally, some
metathesis (double displacement) reactions will be performed.
Part A is concerned with identification of selected inorganic compounds by their names,
chemical formulas, physical states, colors, crystals and solubility in water.
Part B is concerned with metathesis reactions between these salts according to following steps,
taking the reaction between silver nitrate and sodium chloride as an example:
Step 1: Write chemical formulas of reactants as follows:
AgNO3 + NaCl
Step 2: Write the metathesis reaction in molecular form by exchanging cations with anions of
reactants as follows:
AgNO3 + NaCl → AgCl + NaNO3
Step 3: Observation of reactants before mixing will determine the solubility of compounds. If
soluble, reactants will be written in ionic form as follows.
Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq) →
Step 4: If reaction occurs, it will be observed by either:
a- Formation of precipitate
b- Evolution of gas.
c- Absorption or release of heat (tube will be either cold or hot).
d- Change in color.
e- Change in acidity.
In this example a white precipitate of AgCl is formed, thus, the reaction will be represented by a
net ionic equation as follows:
Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq) → AgCl (s) + Na+(aq) + NO-3 (aq)
Step 5: Sodium and nitrate ions are called spectators since nothing happen to them during
reaction, so they could be excluded from final equation which is called net ionic equation as
follows:
Ag+ (aq) + Cl- (aq) → AgCl (s)
Experimental
A. Identification
About twelve inorganic compounds will be displayed as solid crystals in watch glasses and
solutions in test tubes.
1. Observe and characterize the physical properties of solid crystals and solubilities from test
tubes.
2. Record your observations on report sheet.
3. Try to make classifications related to periodic properties.
B. Metathesis Reactions
I. Test Solutions
1. Arrange 10 clean test tubes in your test tube rack and label each tube.
2. Prepare the solutions according to the following list.
Test tube
1
2
3
4
5
6
7
8
9
10
11
12
Solution
Several crystals of FeCl3.6H2O in 2 mL water
Several crystals of Na2CO3 in 2 mL water
Several crystals of BaCl2.2H2O in 2 mL water
Several crystals of Na3PO4.12H2O in 2 mL water
Several crystals of NH4NO3
Several crystals of NiCl2.6H2O in 2 mL water
Several crystals of CuSO4.5H2O in 2 mL water
Several crystals of CoCl2.6H2O in 2 mL water
Solution of 1.0 M HCl (2.5 mL)
Several crystals of AgNO3 in 2 mL water
Solution of 1.0 M NaOH (2.5 mL)
Several crystals of CaCO3
II. Metathesis Reactions
1. Perform reactions in clean test tubes as follows:
a. Combine half of #1 and one third of # 11.
b. Combine one third of #2 and one third of # 7.
c. Combine half of #6 and one third of # 2.
d. Combine half of #3 and one third of # 7.
e. Add half #4 to the reminder of #7.
f. Add half #8 to the reminder of #1.
g. Add one third #11 to #5. Heat over a soft flame (smell cautiously).
h. Add half #4 to #12.
i. Add the reminder of #9 to the reminder of #11. Observe temperature changes.
j. Add the reminder of #4 to the reminder of #6.
k. Combine half of #10 and the reminder of #8.
l. Add the reminder of #10 to the reminder of #2.
2. Record your stepwise study of each reaction on lab report according to steps outlined in
introduction.
3. Be sure to observe indications for a chemical reaction.
4. You may need to centrifuge the reaction mixture if you suspect that a precipitate forms.
Experiment Two: Properties of Inorganic Compounds and Metathesis
Reactions
Pre-Laboratory Questions
Student name:
Section:
ID:
Instructor:
1. List five observations to determine if a chemical reaction took place.
2. Which of the following equations represents a metathesis reaction?
a. 3AgNO3 (aq) + AlCl3 (aq) → Al(NO3)3 (aq) + 3AgCl (s)
b. CuSO4 (aq) + Zn (s) → ZnSO4 (aq) + Cu (s)
c. CH4 (g) + 2NO2 (g) → N2 (g) + CO2 (g) + 2H2O(l)
d. CaCO3 (s) + 2HNO3 (aq) → Ca(NO3) (aq) + CO2 (g) + H2O (l)
3. For each selected metathesis reaction in 2 write ionic and net ionic equations
Experiment Two: Properties of Inorganic Compounds and Metathesis
Reactions
Results and Calculations
Student name:
Section:
ID:
Instructor:
A. Identification
Fill in the table physical properties for displayed inorganic compounds as described in
experimental:
No.
Formula
Name
0
1
NaCl
Sodium Chloride
2
3
4
5
6
7
8
9
10
11
12
Remarks:
Physical
state
Solid
Color
White
Crystal
Characteristics
Small, shiny, dry
Solubility
S
B. Metathesis Reactions
For each reaction (a to l) list the observation and write molecular, ionic and net ionic equations.
a. Ferric chloride and sodium hydroxide
Observation: Formation of white precipitate
Chemical Equations:
1. Molecular: FeCl3 (aq) + 3 NaOH (aq) → Fe(OH)3 (s) + 3 NaCl (aq)
2. Ionic: Fe3+(aq) + 3Cl-(aq) + 3Na+ (aq) + 3OH-(aq) → Fe(OH)3 (s) + 3Na+(aq) + 3Cl-(aq)
3. Net ionic: Fe3+(aq) + 3OH-(aq) → Fe(OH)3 (s)
----------------b.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
-----------------c.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
-----------------d.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
-----------------e.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
-----------------f.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
-----------------g.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
-----------------h.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
-----------------i.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
-----------------j.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
------------------
k.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
-----------------l.
Observation:
Chemical Equations:
1. Molecular:
2. Ionic:
3. Net ionic:
-----------------Conclusions: