- Published: November 14, 2021
- Updated: November 14, 2021
- University / College: University of California, Santa Barbara (UCSB)
- Language: English
- Downloads: 27
Purpose:
The purpose of this lab was to determine the type of bonding in some unknown substances based on their physical properties.
Table of Properties:
Properties
Ionic
Molecular
Electrical Conductivity of the compound in aqueous solution
Conduct
Don’t Conduct
Melting and Boiling points
High
Low
Electrical Conductivity of the compound in liquid form
Conduct
Don’t Conduct
Hardness
Hard
Soft
Polar solvents
Can dissolve ionic compounds that ionize.
Can dissolve covalent compounds that ionize.
Procedure:
* Test one: Hardness
* Test two: Dissolve in water and see if it conducts electricity
* Test three: Heat up to see how fast it will melt or boil
1) Carefully read the directions first
2) Gather Materials
– Test tubes, several unknown compounds, conductivity testers, oil, wooden stirring sticks, water, Bunsen burner, test tube racks, goggles.
3) Put on Safety Equipment (goggles)
4) Perform Test One by pressing compounds to see how hard/soft it is
5) List Observations
6) Perform Test Two by getting 4 cups of 20 mL of distilled water
7) Measure out a small quantity of each substance
8) Then put each substance into different cups of water
9) Stir them out
10) Test the conductivity of the compounds using the conductivity testers
11) List Observations
12) Perform Test Three by lighting the Bunsen Burner
13) Put a little bit of each compound into separate test tubes
14) Hold the test tube over the Bunsen Burner flame and Heat for 30 secs
15) List Observations
16) Clean the lab area
17) By using Data, Determine the bond type (Ionic or Molecular) for each compound
Data:
A
B
C
D
Hardness
Very soft, powdery
Soft, harder than A
Soft
Hard when clumped but soft when powdery
Conductivity
Doesn’t conduct
Doesn’t conduct
Conducts electricity
Conducts electricity
Melting/Boiling
Boiled and melted very quickly
Melts and boils quickly
Doesn’t melt, Doesn’t boil
Condensed & clumped
Polarity
Dissolves
Doesn’t dissolve
Doesn’t dissolve
Doesn’t Dissolve
Conclusion:
The purpose of this lab was to determine the type of bonding in some unknown substances based on their physical properties. To start-off, the group gathered required materials, performed the tests, listed observations and cleaned the lab. Afterwards, it determined the bond type of unknown substances. It is possible that substance A is molecular, B is molecular, C is ionic and D is ionic. A is molecular because the compound melted and boiled at much lower temperature (took milliseconds to melt) than ionic compounds did (C and D). It also dissolved in oil and did not conduct electricity in solution. On top of that, it is very soft because covalent compounds are frequently flexible rather than hard. It is also promising that B is molecular.
It did not conduct electricity, melted and boiled at a low boiling point, and was soft when felt. Although it did not dissolve with oil, all other collected data suggests that it is, most likely, a molecular bond. It is determined that substance C is ionic because it did not melt/boil or change physical appearance. It conducted electricity but did not dissolve. Despite the fact it is soft; the is harder than molecular substances. D is ionic because it’s hard, conducted electricity in solution state, did not melt or boil but rather condensed and clumped and it did not dissolve in oil. To improve the lab, the team could perform more tests to make it much easier to determine the bond type.
