To draw the Lewis structure for C2H2Cl2 (dichloroethylene), we start by determining the total number of valence electrons available for bonding. Carbon (C) has 4 valence electrons, hydrogen (H) has 1, and chlorine (Cl) has 7. Thus:
- 2 Carbons: 2 x 4 = 8 valence electrons
- 2 Hydrogens: 2 x 1 = 2 valence electrons
- 2 Chlorines: 2 x 7 = 14 valence electrons
This gives us a total of 8 + 2 + 14 = 24 valence electrons.
Next, we arrange the atoms. The two carbon atoms will bond to each other and will each bond to one hydrogen and one chlorine atom:
H – C = C – H
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Cl Cl
Now, let’s place the remaining electrons. Each of the carbon atoms will use their remaining valence electrons to form a double bond between them, which uses 4 electrons:
H – C = C – H
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Cl Cl
After forming the double bond, we have the following arrangement: each carbon is bonded to one hydrogen, one chlorine, and to each other with a double bond. The Lewis structure reflects that each atom achieves a full octet (or duet in the case of hydrogen).
In summary, the Lewis structure for C2H2Cl2 shows a double bond between the two carbon atoms, with each carbon also bonded to one hydrogen and one chlorine atom, satisfied by the distribution of valence electrons to fulfill the octet rule.