Question

Which of the following bonds are polar: (a) \(\mathrm{B}-\mathrm{F}\), (b) \(\mathrm{Cl}-\mathrm{Cl}\), (c) \(\mathrm{Se}-\mathrm{O}\), (d) \(\mathrm{H}-\mathrm{I}\) ? Which is the more electronegative atom in each polar bond?

Short answer

The polar bonds are B-F, Se-O, and H-I, with the more electronegative atoms being F, O, and I, respectively. The Cl-Cl bond is nonpolar.

Step-by-step solution

a) B-F bond

For the B-F bond, we need to determine the electronegativity difference between boron (B) and fluorine (F). The electronegativities are as follows: - Boron (B): 2.04 - Fluorine (F): 3.98 Electronegativity difference: \(3.98 - 2.04 = 1.94\) Since the electronegativity difference is greater than 0.4, the B-F bond is considered polar. The more electronegative atom in this bond is fluorine (F).

b) Cl-Cl bond

For the Cl-Cl bond, we need to determine the electronegativity difference between the two chlorine (Cl) atoms. Since they are the same atom, the electronegativity difference is 0: Electronegativity difference: \(3.16 - 3.16 = 0\) Since the electronegativity difference is 0, the Cl-Cl bond is considered nonpolar. There is no electronegative atom in this bond.

c) Se-O bond

For the Se-O bond, we need to determine the electronegativity difference between selenium (Se) and oxygen (O). The electronegativities are as follows: - Selenium (Se): 2.55 - Oxygen (O): 3.44 Electronegativity difference: \(3.44 - 2.55 = 0.89\) Since the electronegativity difference is greater than 0.4, the Se-O bond is considered polar. The more electronegative atom in this bond is oxygen (O).

d) H-I bond

For the H-I bond, we need to determine the electronegativity difference between hydrogen (H) and iodine (I). The electronegativities are as follows: - Hydrogen (H): 2.20 - Iodine (I): 2.66 Electronegativity difference: \(2.66 - 2.20 = 0.46\) Since the electronegativity difference is greater than 0.4, the H-I bond is considered polar. The more electronegative atom in this bond is iodine (I). In summary, the polar bonds are B-F, Se-O, and H-I, with the more electronegative atoms being F, O, and I, respectively. The Cl-Cl bond is nonpolar.