Question

question 17
rank the following according to increasing bond polarity (i.e. least polar to most polar).
○ f - cl < f - br < f - br < f - f
○ f - i < f - cl < f - br < f - f
○ f - f < f - cl < f - br < f - i
○ f - f < f - i < f - br < f - cl

Explanation:

Step1: Understand bond polarity

Bond polarity depends on electronegativity difference. $\text{F-F}$ has zero difference (non - polar).

Step2: Analyze other bonds

Electronegativity of $\text{F} = 4.0$, $\text{Cl}=3.0$, $\text{Br}=2.8$, $\text{I}=2.5$.
For $\text{F - I}$: $\Delta \text{EN}=4.0 - 2.5=1.5$.
For $\text{F - Br}$: $\Delta \text{EN}=4.0 - 2.8 = 1.2$.
For $\text{F - Cl}$: $\Delta \text{EN}=4.0 - 3.0=1.0$.

Answer:

$\text{F - F}<\text{F - I}<\text{F - Br}<\text{F - Cl}$