Questions: Consider the differences between ionic, nonpolar covalent, and covalent bonds for the following questions. Are the bonds in each of the following substances ionic, nonpolar covalent, or polar covalent? Select the single best answer for each substance. Substance Type of bond ------ P4 ionic nonpolar covalent polar covalent NaCl ionic nonpolar covalent polar covalent PF3 ionic nonpolar covalent polar covalent BCl3 ionic nonpolar covalent polar covalent NaBr ionic nonpolar covalent polar covalent SCl2 ionic nonpolar covalent polar covalent For those substances with polar covalent bonds (PF3, BCl3, SCl2), arrange them in order of increasing bond polarity.

Solution Steps

To determine the type of bond, we need to consider the nature of the elements involved and their electronegativity differences:

1. $\mathrm{P}_{4}$: Phosphorus atoms are identical, so the bond is nonpolar covalent.
2. NaCl: Sodium (Na) and chlorine (Cl) have a significant electronegativity difference, resulting in an ionic bond.
3. $\mathrm{PF}_{3}$: Phosphorus (P) and fluorine (F) have different electronegativities, leading to a polar covalent bond.
4. $\mathrm{BCl}_{3}$: Boron (B) and chlorine (Cl) have different electronegativities, resulting in a polar covalent bond.
5. NaBr: Sodium (Na) and bromine (Br) have a significant electronegativity difference, resulting in an ionic bond.
6. $\mathrm{SCl}_{2}$: Sulfur (S) and chlorine (Cl) have different electronegativities, leading to a polar covalent bond.

For substances with polar covalent bonds ($\mathrm{PF}_{3}$, $\mathrm{BCl}_{3}$, $\mathrm{SCl}_{2}$), we arrange them by increasing bond polarity. Bond polarity is determined by the difference in electronegativity between the bonded atoms:

• $\mathrm{BCl}_{3}$: Boron and chlorine have a smaller electronegativity difference compared to the others.
• $\mathrm{SCl}_{2}$: Sulfur and chlorine have a moderate electronegativity difference.
• $\mathrm{PF}_{3}$: Phosphorus and fluorine have the largest electronegativity difference, making it the most polar.

Final Answer