Page 1 V2003
As you know, one can predict the shape and some properties of molecules by using 2 simple rules of
thumb: 1) Atoms and lone pairs of electrons take up space
2) In a molecule or ion, atoms and lone pairs orient themselves in space to give everything the
most possible room.
These simple rules have been codified as Valence Shell Electron Pair Repulsion theory (VSEPR).
BEFORE YOU COME TO LAB, READ pp 60-66 in Munowitz on VSEPR.
Page 2 V2003
While you are waiting for the IR, complete the following questions for each molecule or ion listed.
1a. Hydronium ion,
Give formula: H3O+,
Give total # of valence electrons: 8 e-.
Its 3-D shape is: tetrahedral (pyramidal) ,
Its bond angles are:  109.50 ,
Its bonds are: O  H bonds polar,
The whole molecule is polar / nonpolar (It’s charged).
It looks like:
+
"
O
H
H
"
1. NH3
Give NAME: __ammonia______________________:
Give total # of valence electrons: __8____
Its 3-D shape is: __tetrahedral (pyramidal if you ignore lone pairs)________________
Its bond angles are: _ 109.50 ________________
Its bonds are: _Polar/nonpolar (circle one)
The whole molecule is polar / nonpolar (Circle one)
Is it a weak acid or a weak base (Circle one)?
Write the net ionic reaction of NH3 and water. ____NH3 + H2O  NH4+ + OHIt looks like:
"
N
H
H
H
Page 3 V2003
2. Ammonium ion
Give FORMULA: _____NH4+___________________:
Give total # of valence electrons: ____8__
Its 3-D shape is: _______Tetrahedral___________
Its bond angles are: ______ 109.50 ____________
Its bonds are: Polar/nonpolar (circle one)_______polar____________
The whole molecule is polar / nonpolar (circle one)_____polar______________
Is it a weak acid or a weak base (Circle one)?
Write the net ionic reaction of NH4+ and water. ____ NH4+ + H2O  NH3 + H3O+
It looks like:
+
H
N
H
H
H
3. PO43Give NAME: _____phosphate ion___________________:
Give total # of valence electrons: ___32___
Its 3-D shape is: _______tetrahedral___________
Its bond angles are: _____109.5____________
Its bonds are: Polar/nonpolar (circle one)___________________
The whole molecule is polar / nonpolar (circle one)___________________
Phosphoric acid (H3PO4) is a weak acid. Is PO43- a weak acid or a weak base (circle one)?
Write the net ionic reaction of PO43- and water. __PO43- + H2O  HPO42- + OHIt looks like:
3O
P
O
O
O
Page 4 V2003
4. Boron trifluoride,
Give FORMULA: ____BF3____________________:
Give total # of valence electrons: __24____
Its 3-D shape is: ______trigonal planar____________
Its bond angles are: ___120o______________
Its bonds are: Polar/nonpolar (circle one)___________________
The whole molecule is polar / nonpolar (circle one)___________________
Is boron trifluoride a Lewis acid or a Lewis base (circle one)__can accept a pair of e-_________________?
It looks like:
F
F
B
F
5. AsH3
Give NAME: _____Arsenic trihydride___________________:
Give total # of valence electrons: _8_____
Its 3-D shape is: __tetrahedral (pyramidal)________________
Its bond angles are: ___109.5o______________
Its bonds are: Polar/nonpolar (circle one)___________________
The whole molecule is polar / nonpolar (circle one)___________________
It looks like:
As
H
H
H
Page 5 V2003
6. PF3Cl2
Give total # of valence electrons: _40_____
Its 3-D shape is: _trigonal bipyramidal_________________
Its bond angles are: __90o & 120o_______________
Its bonds are: Polar/nonpolar (circle one)___________________
The whole molecule is polar / nonpolar (circle one)___________________
It looks like:
Cl
F
F
P
F
Cl
7. Bromine trifluoride
Give FORMULA: _____BrF3___________________:
Give total # of valence electrons: ___28___
Its 3-D shape is: ___ttrigonal bipyramidal/ trigonal if you ignore the lone pairs_______________
Its bond angles are: ___120o______________
Its bonds are: Polar/nonpolar (circle one)___________________
The whole molecule is polar / nonpolar (circle one)___________________
It looks like:
"
F
Br
F
F
"
Page 6 V2003
8. XeF4O
Give total # of valence electrons: ___42___
Its 3-D shape is: octahedral (square pyramidal if you ignore lone pairs)
Its bond angles are: __90o & 120o_______________
Its bonds are: Polar/nonpolar (circle one)___________________
The whole molecule is polar / nonpolar (circle one)___________________
It looks like:
O
F
F
Xe
F
F
"
9. SbF6-
Give total # of valence electrons: _____48_
Its 3-D shape is: _____octahedral_____________
Its bond angles are: ___120o & 90o______________
Its bonds are: Polar/nonpolar (circle one)___________________
The whole molecule is polar / nonpolar (circle one)__it’s an ion_________________
It looks like:
F
F
F
Sb
F
F
F
Page 7 V2003
10. ClO2Give NAME: ____chlorite ion____________________:
Give total # of valence electrons: _20_____
Its 3-D shape is: __tetrahedral (bent if you don’t count lone pairs)________________
Its bond angles are: _____109.5o____________
Its bonds are: Polar/nonpolar (circle one)___________________
The whole molecule is polar / nonpolar (circle one)___________________
Write the name and formula of the conjugate acid of ClO2-. _____HClO2 chlorous acid_______________
NaClO2 is a weak base. It is soluble in water. Name it: ___sodium hypochlorite_______________
Write the net ionic equation for the reaction of NaClO2 and water.
Na+ + ClO2- + H2O  Na+ + HClO2 + OH-
It looks like:
"
Cl
O
:
O
Page 8 V2003
11. . chloro-trifluoromethane, ClF3C
Give total # of valence electrons: __32____
Its 3-D shape is: ____tetrahedral______________
Its bond angles are: ___109.5o______________
Its bonds are: Polar/nonpolar (circle one)___________________
The whole molecule is polar / nonpolar (circle one)___________________
It looks like:
Cl
C
F
F
F
12. Sulfate ion
Give FORMULA: _____SO42-___________________:
Give total # of valence electrons: _32_____
Its 3-D shape is: ____tetrahedral______________
Its bond angles are: ______1090___________
Its bonds are: Polar/nonpolar (circle one)________polar___________
The whole molecule is polar / nonpolar (circle one)_____polar (it’s an ion)______________
The name and formula of the conjugate acid of sulfate ion is: ___H 2SO4 sulfuric acid_________________
2O
S
O
It looks like:
13. Ethylene, H2CCH2,
O
O
Page 9 V2003
Give total # of valence electrons: __12____
Its 3-D shape is: _____trigonal__- trigonal___________
Its bond angles are: ______120o___________
Its bonds are: Polar/nonpolar (circle one)____nonpolar_______________
The whole molecule is polar / nonpolar (circle one)_____nonpolar______________
It looks like:
H
C
C
H
H
H
14. Methyl ammonium ion, CH3NH3+,
Give total # of valence electrons: ___14___
Its 3-D shape is: ______tetrahedral - tetrahedral____________
Its bond angles are: _109o________________
Its bonds are: Polar/nonpolar (circle one)__C-H relatively nonpolar, C-N & N-H polar______________
The whole molecule is polar / nonpolar (circle one)________polar___________
Methyl ammonium chloride, CH3NH3Cl, is soluble in water and is a weak acid.
Write the net ionic equation for its reaction with NaOH:
CH3NH3+ + Cl- + Na+ + OH-  CH3NH2 + Cl- + Na+ + H2O
It looks like:
H
H
H
+
C
H
N
H
H
Page 10 V2003
15, Phosgene, COCl2 (A deadly nerve gas), ,
Give total # of valence electrons: ___26___
Its 3-D shape is: ____trigonal planar______________
Its bond angles are: ___120o______________
Its bonds are: Polar/nonpolar (circle one)____polar_______________
The whole molecule is polar / nonpolar (circle one)______polar_____________
It looks like:
Cl
O
C
Cl
16. CO2,
Give NAME: ___carbon dioxide_____________________:
Give total # of valence electrons: __24____
Its 3-D shape is: _____linear_____________
Its bond angles are: ___180o______________
Its bonds are: Polar/nonpolar (circle one)___polar________________
The whole molecule is polar / nonpolar (circle one)________nonpolar___________
When CO2 is put in water, it makes a weak acid. Write its formula and name it:____H2CO3 Carbonic acid
It looks like:
..
..
..
O
..
C
O
..
Page 11 V2003
17. . CH3OH, Methanol
SEE THE HINTS ON PUTTING TOGETHER ORGANIC MOLECULES
Give total # of valence electrons: __14____
Its 3-D shape is: ___tetrahedral & bent (tetrahedral)_______________
Its bond angles are: __109o_______________
Its bonds are: Polar/nonpolar (circle one)______C-H relatively nonpolar. C-O & O-H polar___________
The whole molecule is polar / nonpolar (circle one)_______polar____________
It looks like:
H
:
:
O
C
H
H
H
18. CH3CH2 OH, ethanol
SEE THE HINTS ON PUTTING TOGETHER ORGANIC MOLECULES
Give total # of valence electrons: _20_____
Its 3-D shape is: __tetrahedral-_tetrahedral & bent_______________
Its bond angles are: ___109o______________
Its bonds are: Polar/nonpolar (circle one) __C-C nonpolar, C-H relatively nonpolar. C-O & O-H
polar____
The whole molecule is polar / nonpolar (circle one)______polar_____________
It looks like:
:
H
H
H
O
:
C
C
H
H
H
Page 12 V2003
19. CH3 CH2CH2 OH, propanol
SEE THE HINTS ON PUTTING TOGETHER ORGANIC MOLECULES
Give total # of valence electrons: _26_____
Its 3-D shape is: _tetrahedral-tetrahedral-tetrahedral-bent(Tetrahedral)___________
Its bond angles are: ___109o______________
Its bonds are: Polar/nonpolar (circle one)__C -C nonpolar, C-H relatively nonpolar. C-O & O-H
polar____
The whole molecule is polar / nonpolar (circle one)__polar_________________
It looks like:
H
H
H
C
C
H
H
H
H
C
O
:
:
H