Statement (I) : The boiling points of alcohols and phenols increase with increase in the number of C -atoms.
Statement (II) : The boiling points of alcohols and phenols are higher in comparison to other class of compounds such as ethers, haloalkanes.
In the light of the above statements, choose the correct answer from the options given below :
Solution
<p>$\textbf{Statement (I):}$ </p>
<p><p>As the number of carbon atoms in alcohols or phenols increases, the molecule becomes larger, which in turn enhances the van der Waals (dispersion) forces between the molecules.</p></p>
<p><p>Stronger intermolecular forces require more energy (i.e., higher temperature) to overcome, leading to higher boiling points.</p></p>
<p><p>Therefore, Statement (I) is true.</p></p>
<p>$\textbf{Statement (II):}$ </p>
<p><p>Alcohols and phenols have a hydroxyl group ($-OH$) that can form hydrogen bonds, which are significantly stronger than the dipole-dipole interactions typically seen in ethers or the interactions in haloalkanes.</p></p>
<p><p>This stronger hydrogen bonding means that alcohols and phenols have higher boiling points compared to ethers and haloalkanes of similar molecular weight.</p></p>
<p><p>Hence, Statement (II) is also true.</p></p>
<p>Based on the above points, the correct answer is:</p>
<p>Option B: Both Statement I and Statement II are true.</p>
About this question
Subject: Chemistry · Chapter: Alcohols, Phenols and Ethers · Topic: Preparation and Properties of Alcohols
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