Predict the molecular and bond angle for each molecule or ion given below: SO3, ClO3-, NF3, SO42-
Here is SO3. You can find the others on google.com
http://www.google.com/search?q=lewis+structure+SO3&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a
To predict the molecular and bond angle for each molecule or ion, we need to determine their molecular geometry.
1. SO3 (Sulfur trioxide):
To determine the molecular geometry of SO3, we can use the VSEPR (Valence Shell Electron Pair Repulsion) theory. SO3 has a central sulfur atom surrounded by three oxygen atoms. The sulfur atom forms three sigma bonds with the three oxygen atoms. According to VSEPR theory, when there are three electron pairs (two bonding and one lone pair) around the central atom, the molecular geometry is trigonal planar. Therefore, SO3 has a trigonal planar geometry.
The bond angles in a trigonal planar molecule are all 120 degrees.
2. ClO3- (Chlorate ion):
To determine the molecular geometry of ClO3-, we again use VSEPR theory. ClO3- has a central chlorine atom surrounded by three oxygen atoms and one extra electron giving it a -1 charge. The chlorine atom forms three sigma bonds with the three oxygen atoms. When there are four electron pairs (three bonding and one lone pair) around the central atom, the molecular geometry is tetrahedral. However, since there is one lone pair, it induces a bent shape. Therefore, ClO3- has a bent or trigonal pyramidal geometry.
The bond angles in a bent molecule are less than 120 degrees.
3. NF3 (Nitrogen trifluoride):
To determine the molecular geometry of NF3, we once again use VSEPR theory. NF3 has a central nitrogen atom surrounded by three fluorine atoms. The nitrogen atom forms three sigma bonds with the three fluorine atoms. When there are four electron pairs (three bonding and one lone pair) around the central atom, the molecular geometry is tetrahedral. The presence of one lone pair causes the molecular geometry to be trigonal pyramidal.
The bond angles in a trigonal pyramidal molecule are less than 109.5 degrees.
4. SO42- (Sulfate ion):
To determine the molecular geometry of SO42-, we use VSEPR theory. SO42- has a central sulfur atom surrounded by four oxygen atoms and two extra electrons giving it a -2 charge. The sulfur atom forms four sigma bonds with the four oxygen atoms. When there are five electron pairs (four bonding and one lone pair) around the central atom, the molecular geometry is trigonal bipyramidal. However, since there are two lone pairs, it induces an overall bent shape.
The bond angles in a bent molecule are less than 120 degrees.
In summary:
- SO3: Molecular geometry is trigonal planar, with bond angles of 120 degrees.
- ClO3-: Molecular geometry is bent or trigonal pyramidal, with bond angles less than 120 degrees.
- NF3: Molecular geometry is trigonal pyramidal, with bond angles less than 109.5 degrees.
- SO42-: Molecular geometry is bent, with bond angles less than 120 degrees.