The most reasonable Lewis structure for HOCl is Select one: H: C: %: H: o: Cl: H: o: :Ct: H: O: : CI:
The Correct Answer and Explanation is:
The most reasonable Lewis structure for HOCl (hypochlorous acid) is:
H–O–Cl
Or, in Lewis structure format with lone pairs:
H–O–Cl
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- Hydrogen (H) forms a single bond with oxygen (O).
- Oxygen (O) forms a single bond with chlorine (Cl).
- Oxygen has two lone pairs of electrons, and chlorine has three lone pairs.
Explanation
The Lewis structure is a way to represent the bonding between atoms and the lone pairs of electrons in a molecule. For HOCl, we analyze each atom:
- Hydrogen (H) has 1 valence electron and can form only 1 bond. It bonds to oxygen.
- Oxygen (O) has 6 valence electrons. It typically forms 2 bonds and has 2 lone pairs.
- Chlorine (Cl) has 7 valence electrons. It typically forms 1 bond and has 3 lone pairs.
We start by connecting the atoms. Since hydrogen can only make one bond, and oxygen usually bonds to both hydrogen and chlorine, the backbone is H–O–Cl.
- The H–O bond uses 2 electrons (1 from H, 1 from O).
- The O–Cl bond also uses 2 electrons (1 from each atom).
- This accounts for 4 bonding electrons (2 bonds).
- The oxygen still needs 4 more electrons (2 lone pairs) to complete its octet.
- Chlorine needs 6 more electrons (3 lone pairs) to reach its octet.
The total number of valence electrons is:
- H: 1
- O: 6
- Cl: 7
Total = 14 electrons
We’ve used:
- 4 electrons in bonds (2 bonds)
- 4 electrons on oxygen (2 lone pairs)
- 6 electrons on chlorine (3 lone pairs)
Total = 14 electrons, which matches.
This structure is the most reasonable because:
- All atoms follow the octet rule (except hydrogen, which follows the duet rule).
- The formal charges on all atoms are zero.
- Oxygen is the central atom bonded to both hydrogen and chlorine, which reflects oxygen’s higher electronegativity compared to chlorine.
Therefore, the correct Lewis structure for HOCl is H–O–Cl, with lone pairs shown on oxygen and chlorine
.