Question

Which of the following incorrectly shows the bond polarity? Show the correct bond polarity for those that are incorrect.

a. δ+H—Fδ–
b. δ+Cl—Iδ–
c. δ+Si—Sδ–
d. δ+Br—Brδ–
e. δ+O—Pδ–

Answer 1

The incorrect bond polarities among the given options are δ+Cl—Iδ– (should be δ–I—Clδ+), δ+Si—Sδ– (is correct as shown), and δ+Br—Brδ– (should show no δ as it's nonpolar). Correctly identifying the polarity of bonds involves knowing the relative electronegativities of the bonded atoms.

Step-by-step explanation:

The question addresses the polarity of chemical bonds, specifically relating to the correct representation of partial charges in diatomic molecules. Polar covalent bonds have unequal sharing of electrons due to differences in electronegativity (EN) between bonded atoms, resulting in partial positive (δ+) and negative (δ–) charges.

Let's evaluate each given bond:

1. δ+H—Fδ– is correct. Fluorine is more electronegative than hydrogen.
2. δ+Cl—Iδ– is incorrect. Iodine is more electronegative than chlorine, so it should be δ–I—Clδ+.
3. δ+Si—Sδ– is incorrect. Sulfur is more electronegative than silicon, so it should be δ+Si—Sδ–.
4. δ+Br—Brδ– is incorrect. As both atoms are bromine, they have the same electronegativity; hence the bond is nonpolar covalent, so no δ+ or δ– should be assigned.
5. δ+O—Pδ– is correct. Oxygen is more electronegative than phosphorus.

Answer 2

The bond polarity indicates the distribution of electrical charge across a bond based on the differences in electronegativity between the bonded atoms. Option b, Cl—I, should be corrected to δ-Cl—Iδ+, option c, Si—S, should be δ-Si—Sδ+, and option d, Br—Br, should indicate a nonpolar bond without partial charges.

Step-by-step explanation:

We can assess the polarity of a bond by looking at the electronegativity (EN) values of the atoms involved; the atom with the higher electronegativity will have a partial negative charge (δ–), while the atom with the lower electronegativity will have a partial positive charge (δ+). Now let's examine the given bond polarities and correct them if needed:

• a. δ+H—Fδ– (Correct, as fluorine is more electronegative than hydrogen.)
• b. δ+Cl—Iδ- (Incorrect, as chlorine and iodine have similar electronegativities, but if a difference exists, Cl is slightly more electronegative than I, so it should be δ-Cl—Iδ+.)
• c. δ+Si—Sδ- (Incorrect, as sulfur is more electronegative than silicon, the correct representation is δ-Si—Sδ+.)
• d. δ+Br—Brδ- (Incorrect, because bromine atoms are identical and share equal electronegativity, hence the bond is nonpolar with no partial charges, so it should be Br—Br.)
• e. δ+O—Pδ- (Correct, as oxygen is more electronegative than phosphorus.)