Chemistry 162
Name(s):
Activity 5: VSEPR, molecular shapes and polarity
Draw the correct Lewis dot structure that you determined in Activity 4, and use
them and the VSEPR rules to provide the following information:
a. H2CO (formaldehyde)
Number of lone pairs =
Number of atoms bonded to the central atom =
Electron group number (sum of previous two numbers) =
Arrangement of electron groups =
Actual molecular shape (ignoring the lone pairs) =
Ideal central bond angle =
Deviations from ideal bond angle (Y/N)?
If so, describe with ">" or "<"
b. NOBr
Number of lone pairs =
Number of atoms bonded to the central atom =
Electron group number (sum of previous two numbers) =
Arrangement of electron groups =
Actual molecular shape (ignoring the lone pairs) =
Ideal central bond angle =
Deviations from ideal bond angle (Y/N)?
If so, describe with ">" or "<"
c. NO2+ (nitrite cation)
Number of lone pairs =
Number of atoms bonded to the central atom =
Electron group number (sum of previous two numbers) =
Arrangement of electron groups =
Actual molecular shape (ignoring the lone pairs) =
Ideal central bond angle =
Deviations from ideal bond angle (Y/N)?
If so, describe with ">" or "<"
d. NO2- (nitrite anion)
Number of lone pairs =
Number of atoms bonded to the central atom =
Electron group number (sum of previous two numbers) =
Arrangement of electron groups =
Actual molecular shape (ignoring the lone pairs) =
Ideal central bond angle =
Deviations from ideal bond angle?
If so, describe with ">" or "<"
e. POCl3
Number of lone pairs =
Number of atoms bonded to the central atom =
Electron group number (sum of previous two numbers) =
Arrangement of electron groups =
Actual molecular shape (ignoring the lone pairs) =
Ideal central bond angle =
Deviations from ideal bond angle?
f. SF6 (sulfur hexafluoride)
If so, describe with ">" or "<"
Number of lone pairs =
Number of atoms bonded to the central atom =
Electron group number (sum of previous two numbers) =
Arrangement of electron groups =
Actual molecular shape (ignoring the lone pairs) =
Ideal central bond angle =
Deviations from ideal bond angle?
If so, describe with ">" or "<"
2. Draw Lewis dot structures (with correct angles) for the six species in the
previous problem. Then draw the individual dipole moments along each polar
covalent bond. Finally, draw the net dipole moment for the whole ion or
molecule, or write zero polarity if there is no net dipole moment.