12th grade chemistry organic explainer video target for NEET 2026 in indian medical entrance exam---3. $\text{CH}_2\text{ClCH}_2\text{OH}$ is stronger acid than $\text{CH}_3\text{CH}_2\text{OH}$ because:
a) +$IE$ of $\text{Cl}$ disperses –ve chare on $\text{O}$ –atom to produce more stable anion
b) –$IE$ of $\text{Cl}$ disperses –ve charge on $\text{O}$ –atom to produce more stable anion
c) +$IE$ of $\text{Cl}$ increases –ve charge on $\text{O}$ –atom to alcohol
d) None of the above
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Let's analyze why 2-chloroethanol is a stronger acid than ethanol. We have four options to consider. The key lies in understanding how the chlorine atom affects the stability of the conjugate base formed when these alcohols lose a proton.
The strength of an acid depends on the stability of its conjugate base. When ethanol loses a proton, it forms the ethoxide ion. When 2-chloroethanol loses a proton, it forms the 2-chloroethoxide ion. The more stable the conjugate base, the stronger the parent acid.
Chlorine is highly electronegative and exerts a negative inductive effect. This means it withdraws electron density from the carbon chain, which in turn pulls electrons away from the oxygen atom. This electron withdrawal disperses the negative charge on the oxygen, making the 2-chloroethoxide ion more stable than the ethoxide ion.
Let's compare the stability of both conjugate bases. The ethoxide ion has alkyl groups that show a positive inductive effect, concentrating the negative charge on oxygen, making it less stable. In contrast, the 2-chloroethoxide ion has chlorine with a negative inductive effect that disperses the negative charge, making it more stable. Since a more stable conjugate base corresponds to a stronger acid, 2-chloroethanol is indeed stronger than ethanol.
Now let's analyze each option. Option A is incorrect because chlorine has a negative inductive effect, not positive. Option C is wrong because the effect disperses charge rather than increasing it. Option D is incorrect since we have a correct answer. Option B is correct: the negative inductive effect of chlorine disperses the negative charge on the oxygen atom, producing a more stable anion. Therefore, the answer is B.