Which of the following correctly shows the direction of polarity and partial charges for the H–Cl bond?

• A. H^{ext{δ-}}–Cl^{ext{δ-}}
• B. H^{ext{δ-}}–Cl^{ext{δ+}}
• C. H^{ext{δ+}}–Cl^{ext{δ+}}
• D. H^{ext{δ+}}–Cl^{ext{δ-}}

Answer: (D)

Verified step by step guidance

1. Step 1: Understand that polarity in a bond arises due to differences in electronegativity between the two atoms involved. Electronegativity is the tendency of an atom to attract shared electrons in a chemical bond.
2. Step 2: Identify the electronegativities of hydrogen (H) and chlorine (Cl). Chlorine is more electronegative than hydrogen, meaning it attracts the bonding electrons more strongly.
3. Step 3: Because chlorine attracts electrons more strongly, the shared electron pair in the H–Cl bond will be closer to chlorine, creating a partial negative charge (δ-) on Cl and a partial positive charge (δ+) on H.
4. Step 4: Represent the polarity direction with an arrow pointing from the less electronegative atom (H) to the more electronegative atom (Cl), indicating the shift of electron density.
5. Step 5: Conclude that the correct representation of the bond polarity is \(\mathrm{H^{\delta+} - Cl^{\delta-}}\), showing hydrogen with a partial positive charge and chlorine with a partial negative charge.