Name:
Grade:
Group Members:
Ionic and Covalent
ID:
Date:
1. Introduction:
In this experiment, you will discover some properties of strong electrolytes, weak
electrolytes, and non-electrolytes by observing the behavior of these substances
in aqueous solutions. You will determine these properties using a Conductivity
Probe. When the probe is placed in a solution that contains ions, and thus has the
ability to conduct electricity, an electrical circuit is completed across the
electrodes that are located on either side of the hole near the bottom of the
probe body (see Figure 1). This results in a conductivity value that can be read by
the computer. The unit of conductivity used in this experiment is the micro
Siemens per centimeter, or µS/cm.
Figure 1
Ionic and covalent compounds have different properties ( physical state ,high or
low melting and boiling points ) that reflect a difference in their bonding type .
In each part of the experiment, you will be observing a different property of
ionic and covalent compounds.
The objective of the experiment is to:

Examine the physical state of ionic and covalent compounds.

Use a Conductivity Probe to measure the conductivity of solutions.

Determine the kind of the compounds (ionic or covalent) using conductivity
.

Search for the difference in the melting and boiling points of ionic and
covalent compounds.

Relate the type of the bond to the difference in the properties of ionic
and covalent compounds.
2. Materials and Equipment:

Vernier computer interface

Verneir conductivity probe

250 mL Beaker

Wash bottle with distilled water.

Tissues

0.05 M NaCl

0.05 M sugar ( C6H12O6 )

Tap water

Distilled water
3. Procedure:
Part I: conductivity Comparison
1. Obtain and wear goggles! CAUTION: Handle the solutions in this experiment
with care. Do not allow them to contact your skin. Notify your teacher in the
event of an accident.
2. The Conductivity Probe is already attached to the interface. It should be set
on the 0–20000 µS/cm position.
3. Obtain the 0.05 M NaCl solution.
4. Follow the following steps to measure the conductivity.
a. Carefully lower the Conductivity Probe into the solution until the hole
near the probe end is completely submerged. Important: Since the two
electrodes are positioned on either side of the hole, this part of the
probe must be completely submerged.
b. Briefly swirl the beaker contents. When the reading has stabilized,
record the value.
c. Before testing the next solution, clean the electrodes by surrounding
them with a 250 mL beaker and rinsing them with distilled water. Blot
the outside of the probe end dry using a tissue. It is not necessary to
dry the inside of the hole near the probe end.
5. Repeat the Step 4 for other solutions (0.05 M Sugar, Distilled water and tap
water)
.
Part II: Predict the conductivity of solid NaCl and solid Sugar
Part III: Melting and boiling points Comparison.
Compare the melting and the boiling points of sodium chloride and sugar. (Use
different resources)
4. Observations and Results:
Parts I and II: Conductivity
Solution
Solid NaCl
NaCl solution,0.05M
Solid Sugar
Solution of sugar, 0.05 M
Distilled water
Tap water
Part III: Melting points
Sugar MP:………….
NaCl MP: ………..
Conductivity (µS/cm)
5. Discussion, Analysis and Interpretation:
1. Does the second sugar solution appear to be molecular, ionic?
2. Does solid sodium chloride have more conductivity than sodium chloride
solution? Why?
3. Compare the conductivity of sugar solution and sodium chloride solution .
Explain.
4. Which material has higher MP, NaCl or Sugar? Explain
6. Conclusion