Question

Which of the following is the correct order of the reactivity of given nucleophiles when treated with \( \text{CH}_3\text{Br} \) in methanol? \( \text{F}^- \), \( \text{I}^- \), \( \text{C}_2\text{H}_5\text{O}^- \), \( \text{C}_6\text{H}_5\text{O}^- \)

• A. \( \text{I}^->\text{C}_2\text{H}_5\text{O}^->\text{C}_6\text{H}_5\text{O}^->\text{F}^- \)
• B. \( \text{I}^->\text{F}^->\text{C}_2\text{H}_5\text{O}^->\text{C}_6\text{H}_5\text{O}^- \)
• C. \( \text{C}_2\text{H}_5\text{O}^->\text{F}^->\text{I}^->\text{C}_6\text{H}_5\text{O}^- \)
• D. \( \text{C}_6\text{H}_5\text{O}^->\text{I}^->\text{F}^->\text{C}_2\text{H}_5\text{O}^- \)

Hint:

The reactivity of nucleophiles is determined by their size and polarizability. Larger, more polarizable anions like \( \text{I}^- \) are more reactive than smaller anions like \( \text{F}^- \).

Answer 1

The Correct Option is A

Step 1: Reactivity of nucleophiles.
The reactivity of nucleophiles follows the trend of their basicity and polarizability. A larger, more polarizable anion or nucleophile will be more reactive in nucleophilic substitution reactions like \( \text{S}_\text{N}2 \). Step 2: Conclusion.
The reactivity order of the given nucleophiles in methanol is: \[ \text{I}^->\text{C}_2\text{H}_5\text{O}^->\text{C}_6\text{H}_5\text{O}^->\text{F}^- \] Final Answer: \[ \boxed{\text{I}^->\text{C}_2\text{H}_5\text{O}^->\text{C}_6\text{H}_5\text{O}^->\text{F}^-} \]