Question

Ethyl alcohol reacts at a faster rate with $HI$ than with $HCl$ in forming the corresponding ethyl halides under identical conditions mainly because:

• A. $HI$, being a stronger acid, protonates ethyl alcohol at oxygen much better and helps substitution.
• B. the bond length in $HI$ is much shorter than that in $HCl$.
• C. $I-$ is a much better leaving group.
• D. $I-$ is a much better nucleophile than $Cl-$.

Answer 1

The correct option is D $I-$ is a much better nucleophile than $Cl-$.

Ethyl alcohol reacts at a faster rate with $HI$ than with $HCl$ in forming the corresponding ethyl halides under identical conditions mainly because $I-$ is a much better nucleophile than $Cl-$
In iodide ion, the negative charge is dispersed on the large ion.

Hence, it is loosely held by the nucleus. Hence, it can be easily given to an electrophile.