Question

Two different molecules have the formula C₂H₂Cl₂. Draw a Lewis structure for each molecule. (All the H and Cl atoms are bonded to carbon. The two carbon atoms are bonded to each other.)

Answer 1

The compounds containing the molecular formula are 1,1-dichloroethene and 1,2-dichloroethene.

Lewis structure for 1,1-dichloroethene:

The number of valence electrons in can be calculated as follows:

Now, draw the skeletal structure ofas follows:

There are 10 valence electrons in the above structure so the remaining valence electrons are 14. Complete octet for terminal atoms by placing 12 valence electrons as lone pairs on atoms.

Place the remaining two lone pair of electrons to form a double bond between the two carbon atoms.

Therefore, Lewis structure for 1,1-dichloroethene is as follows:

Lewis structure for 1,2-dichloroethene:

Similarly draw another structure with the molecular formula as follows:

There are 10 valence electrons in the above structure so the remaining valence electrons are 14. Complete octets for terminal atoms and then central atoms by placing the 12 valence electrons as lone pairs on atoms.

Place the remaining two lone pair of electrons to form a double bond between the two carbon atoms.

Therefore, Lewis structure for 1,2-dichloroethene is as follows: