chem assignment 5

Experiment 5: Molecular Geometry

1

Data Collection and Results Pages Name: ___________________________________ Date: ___________________

Go to the simulation. Run the Model simulator. Answer the following questions using complete sentences. 1. Play with the simulator a bit. Describe the geometry that you find most interesting. 2. What options do you have that you can turn on and off? 3. What additional options do you have on the Real Molecules simulator? 4.Using only single-bonding (the first type) on the Model screen, build molecules according to the following chart and fill in information. Use no Lone Pairs.

Number of Bonds

Molecule Geometry Electron Geometry Bond Angles Drawing

1

2

3

4

EXPERIMENT 5: MOLECULAR GEOMETRY 2

5. Now you will use some lone pairs to see how they affect the molecular shape. Build models with the number of bonds and lone pairs you see in the chart.

6. Do any of the geometry names change if you use double or triple bonds instead of single bonds? If yes, which ones?

Number of Bonds

Number of Lone Pairs

Molecule Geometry

Electron Geometry

Bond Angles Drawing

1 0

2 0

3 0

2 1

4 0

3 1

2 2

1 3

EXPERIMENT 5: MOLECULAR GEOMETRY 3

7. The phrase ‘electron groups’ or ‘electron clouds’ is used in discussions of molecular geometry to mean either a bond or lone pair on the central atom of a molecule. Look at the chart you filled out for question 5. Total up the number of electron groups (bonds and lone pairs) for each row in the chart and write it next to the beginning of each row. How many different totals are there? What are they? 8. Relate the number of electron groups to the electron geometries: No. of Groups Electron Geometry

1 2 3 4

9. Predict the molecular geometry of the following molecules. Build a model of each compound in the Real Molecules simulator. (Turn on and off the lone pairs to see the differences.) Confirm or correct each of your predictions: Compound Predicted Molecule Geometry Actual Molecule Geometry

H2O

CO2

SO2

XeF2

BF3

ClF3

NH3

CH4

SF4

XeF4

BrF5

PCl5

SF6