Which of the following reactions will be the fastest under similar conditions ?

Question

Which of the following reactions will be the fastest under similar conditions ? (A) C2H5OH + HF arrow C2H5F + H2O (B) C2H5OH + HCl arrow C2H5Cl + H2O (C) C2H5OH + HBr arrow C2H5Br + H2O  (D) C2H5OH + HI arrow C2H5I + H2O

Tardigrade Admin · Accepted Answer

HI is the strongest acid and hence it protonates the alcohol most readily. Further, since I- is the strongest nucleophile. Therefore, it attacks the protonated alcohol molecule most easily forming the corresponding alkyl iodide. C2H5OH xrightarrow[ - I-]HI C2H5 - O+H2 xrightarrow[Fast] I-C2H5I + H2O

Q. Which of the following reactions will be the fastest under similar conditions ?

$C_{2} H_{5} O H + H F \to C_{2} H_{5} F + H_{2} O$

$C_{2} H_{5} O H + H Cl \to C_{2} H_{5} Cl + H_{2} O$

$C_{2} H_{5} O H + H B r \to C_{2} H_{5} B r + H_{2} O$

$C_{2} H_{5} O H + H I \to C_{2} H_{5} I + H_{2} O$

Q. Which of the following reactions will be the fastest under similar conditions ?

C2​H5​OH+HF→C2​H5​F+H2​O

C2​H5​OH+HCl→C2​H5​Cl+H2​O

C2​H5​OH+HBr→C2​H5​Br+H2​O

C2​H5​OH+HI→C2​H5​I+H2​O

$C_{2} H_{5} O H + H F \to C_{2} H_{5} F + H_{2} O$

$C_{2} H_{5} O H + H Cl \to C_{2} H_{5} Cl + H_{2} O$

$C_{2} H_{5} O H + H B r \to C_{2} H_{5} B r + H_{2} O$

$C_{2} H_{5} O H + H I \to C_{2} H_{5} I + H_{2} O$