Draw the best Lewis structure includes _ One double bond, one single bond, and one lone (unshared) electron pair on O Two single bonds and two lone (unshared) electron pairs on O Two double bonds and two lone (unshared) electron pairs on O Two double bonds and no lone (unshared) electron pairs on O Draw the best Lewis structure for the molecule OCl2 (the oxygen atom is in the center). Complete the sentence: My best Lewis structure includes _ One double bond, one single bond, and one lone (unshared) electron pair on O Two single bonds and two lone (unshared) electron pairs on O Two double bonds and two lone (unshared) electron pairs on O Two double bonds and no lone (unshared) electron pairs on O
The Correct Answer and Explanation is:
Correct answer:
Two single bonds and two lone (unshared) electron pairs on O
Explanation (approx. 300 words):
To determine the best Lewis structure for OCl₂ (oxygen dichloride), we follow a systematic approach based on valence electrons, octet rule, and minimizing formal charges.
Step 1: Count total valence electrons.
- Oxygen (O) has 6 valence electrons.
- Each chlorine (Cl) has 7 valence electrons.
So the total is: 6 (O) + 2 × 7 (Cl) = 20 valence electrons.
Step 2: Choose the central atom.
Oxygen is less electronegative than chlorine and is placed in the center. So the structure is Cl–O–Cl.
Step 3: Form single bonds between O and each Cl.
- Each bond uses 2 electrons.
- Two single bonds = 4 electrons used.
Remaining = 20 – 4 = 16 electrons.
Step 4: Distribute remaining electrons to complete octets.
- Place 6 electrons (3 lone pairs) on each Cl to satisfy their octets.
Cl (1 bond + 3 lone pairs = 8 electrons) - That uses 6 + 6 = 12 electrons.
Remaining = 16 – 12 = 4 electrons.
Step 5: Place remaining electrons on central atom (O).
- Oxygen already has 2 bonds (4 electrons).
- Add 2 lone pairs (4 electrons) to complete its octet.
Now oxygen has 4 electrons from lone pairs and 4 from bonds = 8 total.
Step 6: Check formal charges.
- O: 6 valence e⁻ – (4 nonbonding + 2 bonds) = 0
- Cl: 7 valence e⁻ – (6 nonbonding + 1 bond) = 0
Conclusion:
The best Lewis structure has two single bonds (O–Cl), and two lone pairs on the central oxygen atom. This structure satisfies the octet rule and minimizes formal charges for all atoms.
Double bonds are not needed and would give non-zero formal charges or violate the preferred structure of halogens (which typically form one bond only).
Thus, the correct sentence completion is:
My best Lewis structure includes two single bonds and two lone (unshared) electron pairs on O.
