Question

List the bonds \(\mathrm{P}-\mathrm{Cl}, \mathrm{P}-\mathrm{F}, \mathrm{O}-\mathrm{F},\) and \(\mathrm{Si}-\mathrm{F}\) from least polar to most polar.

Short answer

The bonds listed from least polar to most polar are: \(O-F, P-Cl, P-F, Si-F\).

Step-by-step solution

Recall the Electronegativity Values

The first step is to recall the electronegativity values for P, Cl, F, O, and Si from the periodic table. You can refer to a textbook or online resources to find these values. Here's a list of the electronegativities for reference: - P: 2.19 - Cl: 3.16 - F: 3.98 - O: 3.44 - Si: 1.90

Calculate Electronegativity Differences

Now, we will calculate the electronegativity differences for each bond. Remember that electronegativity difference is always a positive number, as we are looking for the absolute difference between the two atoms in the bond. 1. P-Cl: Electronegativity Difference: | 2.19 - 3.16 | = 0.97 2. P-F: Electronegativity Difference: | 2.19 - 3.98 | = 1.79 3. O-F: Electronegativity Difference: | 3.44 - 3.98 | = 0.54 4. Si-F: Electronegativity Difference: | 1.90 - 3.98 | = 2.08

Order the Bonds Based on Polarity

From the electronegativity differences calculated above, it is now time to compare these values to determine the bond order from least polar to most polar. 1. Least polar bond - smallest electronegativity difference: O-F (0.54) 2. P-Cl (0.97) 3. P-F (1.79) 4. Most polar bond - largest electronegativity difference: Si-F (2.08)

Final Answer

The bonds listed from least polar to most polar are: \(O-F, P-Cl, P-F, Si-F\).

Key concepts

Polarity of Bonds

In chemistry, the polarity of a bond describes the unequal sharing of electrons between two atoms. This occurs due to differences in electronegativity, which causes a partial positive charge on one atom and a partial negative charge on the other. When considering bond polarity, it's essential to understand that it reflects how strongly each atom attracts electrons in a bond.

• Nonpolar bonds occur when electrons are shared equally, usually between atoms of similar electronegativity.
• Polar bonds arise when there is an unequal sharing, resulting in a dipole moment that points towards the more electronegative atom.

Bond polarity is crucial because it affects the physical properties e.g., the melting and boiling points, solubility, and reactivity of molecules. For example, polar molecules tend to dissolve in polar solvents, while nonpolar molecules are more soluble in nonpolar solvents.

Electronegativity Differences

Electronegativity is the ability of an atom to attract shared electrons in a chemical bond. Each element has a specific electronegativity value, which is key to determining the polarity of a bond. The greater the difference in electronegativity between two bonded atoms, the more polar the bond will be.

• Small differences in electronegativity (less than 0.5) result in nonpolar covalent bonds.
• Moderate differences (0.5 to 1.7) lead to polar covalent bonds.
• Large differences (greater than 1.7) can indicate ionic bonds.

To calculate the electronegativity difference, simply subtract the smaller electronegativity value from the larger one. This absolute difference tells us how much more one atom will "pull" the electrons toward itself in the bond.
Consider the bonds given in the exercise: - For P-Cl, the difference is 0.97, indicating moderate polarity. - For P-F, the difference is 1.79, suggesting a more polarized bond. - For O-F, the difference is 0.54, one of the least polarized among them. - For Si-F, the difference equals 2.08, which is highly polar and close to being ionic.

Periodic Table Elements

The periodic table is an essential tool in understanding chemical properties and trends, including electronegativity. Every element's position in the periodic table can give insight into its electronegativity, which tends to increase across a period and decrease down a group.

• Elements on the right side, like fluorine, generally have higher electronegativities because they are closer to having a full octet.
• Elements on the left side, such as sodium, often have lower electronegativities.

Knowing the position of an element helps predict its behavior in compounds. For instance, fluorine (\(F\)) has the highest electronegativity on the periodic table, making it extremely powerful in attracting electrons. This makes bonds like Si-F highly polar, as fluorine will attract more electrons compared to silicon (\(Si\)), a less electronegative element.
Paying attention to these trends and values is pivotal for predicting the nature and strength of bonds in chemical reactions and compounds.