Play-Doh Lab
Your Task: You will use Play-Doh to explore the shapes of common compounds.
In the Lab:
1. Determine the Lewis structure for each of the following compounds
OF2
CH4
N2
O2
SeCl6
AsF5
NH3
BF3
BeF2
CI4
CO2
AlH3
HF
2. Determine the shape of the molecule using VSEPR Theory.
3. Create a model of the molecule using Play-Doh and toothpicks. Use half a
toothpick for each bond to help hold them together better and conserve
toothpicks.
4. Using you knowledge of intermolecular forces and VSEPR Theory, predict what
intermolecular forces these molecules would exert on another molecule of the
same compound.
5. Create a data table including the following columns: Number of Valence
Electrons, Lewis Structure, Number of Shared Pairs on the Central Atom, Number
of Unshared Pairs on the Central Atom, Molecular Geometry, 3D Picture of the
Model, and Intermolecular Forces for this Molecule. The columns italicized above
do not need to be completed for nitrogen, oxygen, and hydrogen fluoride.
6. Please note that oxygen and nitrogen exist naturally as O2 and N2. When chemists
refer to “oxygen” or “nitrogen,” we are referring to O2 and N2.
Lab Report:
A) Purpose
B) Analysis Questions
1) Of the compounds above, which ones do you expect to be soluble in
water? Justify your answers.
2) Of the compounds above, which ones do you expect to be soluble in
carbon tetrachloride? Justify your answers.
3) Oxygen, nitrogen, and hydrogen fluoride all have similar geometries.
Which of the three do you expect to have the highest boiling point? Justify
your answer.
4) Based on its intermolecular forces, you would not expect carbon dioxide
to be soluble in water. For example, the solubility of oxygen in water at
25°C and atmospheric pressure is 8.3mg/L. However, carbon dioxide is
fairly soluble in water and has a solubility of 1.45g/L at atmospheric
pressure. Explain why you would not have predicted carbon dioxide’s
higher solubility in water. Then research the reason why carbon dioxide is
fairly soluble in water. Be sure to cite your sources.
C) Conclusions
D) Chart of the 13 compounds