What is the correct Lewis structure for hydrogen chloride, HCL?
a) A
b) B
c) C
d) D
The Correct Answer and Explanation is :
The correct Lewis structure for hydrogen chloride (HCl) is represented by the structure where hydrogen (H) is bonded to chlorine (Cl) with a single covalent bond.
Explanation:
- Valence Electrons: First, we need to determine the number of valence electrons for both hydrogen and chlorine. Hydrogen has one valence electron, while chlorine, being in group 17 of the periodic table, has seven valence electrons. Therefore, the total number of valence electrons available for HCl is 1 (from H) + 7 (from Cl) = 8 valence electrons.
- Bond Formation: In HCl, hydrogen and chlorine share one pair of electrons to form a covalent bond. This bond allows both atoms to achieve a more stable electron configuration. Hydrogen, having only one electron, requires one more to complete its duet (like helium), while chlorine requires one additional electron to complete its octet (like argon).
- Structure Representation: In the Lewis structure, we represent the shared pair of electrons as a single line (covalent bond) between the two atoms. The structure is depicted as H—Cl. In addition to the bond, chlorine will have three lone pairs of electrons remaining, shown as pairs of dots around the chlorine atom.
- Molecular Geometry: The resulting molecular geometry of HCl is linear due to the presence of only two atoms and the absence of lone pairs affecting the bond angle significantly. The bond angle is therefore 180 degrees.
- Polarity: It’s important to note that HCl is a polar molecule. Chlorine is more electronegative than hydrogen, causing the shared electrons to be pulled closer to the chlorine atom, creating a partial negative charge (δ-) on Cl and a partial positive charge (δ+) on H.
In summary, the Lewis structure of HCl is correctly represented by a single line (bond) connecting H and Cl, with Cl having three lone pairs, accurately reflecting the distribution of electrons and the nature of the chemical bond.