Write Lewis dot structures, including unshared pairs, for each of the following. Carbon ha...

Write Lewis dot structures, including unshared pairs, for each of the following. Carbon has four bonds in each compound.

(a) Propane (C3H8)

(b) Methanol (CH4O)

(c) Methyl fluoride (CH3F)

(d) Ethyl fluoride (C2H5F)

Sample Solution (a) The Lewis structure of propane is analogous to that of ethane but the chain is three carbons long instead of two.

The ten covalent bonds in the Lewis structure shown account for 20 valence electrons, which is the same as that calculated from the molecular formula (C3H8). The eight hydrogens of C3H8 contribute 1 electron each and the three carbons 4 each, for a total of 20 (8 from the hydrogens and 12 from the carbons). Therefore, all the valence electrons are in covalent bonds; propane has no unshared pairs.