Question

An ether is more volatile than an alcohol having the same molecular formula. This is due to (a) dipolar character of ethers (b) alcohols having resonance structures (c) intermolecular hydrogen bonding in ethers (d) inter molecular hydrogen bonding in alcohols

Short answer

(d) intermolecular hydrogen bonding in alcohols.

Step-by-step solution

Understand the Question

The question is asking why ethers are more volatile than alcohols with the same molecular formula. Volatility refers to the tendency of a substance to vaporize, which is linked to the strength of intermolecular forces. Stronger forces mean less volatility.

Analyze Ethers

Ethers have a dipolar character due to the presence of an oxygen atom, but they do not form significant hydrogen bonds with other ether molecules, as hydrogen atoms in ethers are not connected to highly electronegative atoms like oxygen.

Analyze Alcohols

Alcohols have an -OH group, allowing them to form significant intermolecular hydrogen bonds. This hydrogen bonding occurs because the hydrogen atom in the -OH group is connected to the highly electronegative oxygen atom, allowing interaction with other molecules' oxygen atoms.

Compare Intermolecular Forces

Because alcohols can form hydrogen bonds, which are a strong type of dipole-dipole attraction, these bonds give them higher boiling points and lower volatility compared to ethers, which lack this hydrogen bonding despite their polar nature.

Evaluate Options

Examine the given options: (a) is incorrect because ether's dipolarity doesn't sufficiently explain its volatility. (b) is incorrect as it incorrectly states that alcohols have resonance structures. (c) is incorrect due to misunderstanding hydrogen bonding in ethers. (d) is correct because alcohols' intermolecular hydrogen bonding makes them less volatile than ethers.

Key concepts

Hydrogen Bonding in Alcohols

Alcohols are fascinating compounds primarily due to their ability to engage in hydrogen bonding. When you look at an alcohol molecule, you notice it has an -OH group. This is where the magic happens. The oxygen atom in the -OH group is highly electronegative, meaning it pulls electrons toward itself, making the hydrogen slightly positive. This setup allows the hydrogen to form a strong connection, or bond, with oxygen atoms from nearby alcohol molecules. This connection is known as hydrogen bonding.

Hydrogen bonding is a type of dipole-dipole attraction and is one of the strongest intermolecular forces. As a result of these bonds, alcohols have a relatively high boiling point because it takes more energy to break these interactions and move the molecules apart into the gas phase. This is why alcohols tend to be less volatile than many other compounds, such as ethers, which lack the capacity for such extensive hydrogen bonding.

Volatility Comparison

Volatility is a term used to describe how easily a substance can vaporize. In simple terms, it's about how fast a liquid turns into a gas. This property is greatly influenced by intermolecular forces.

• Substances with strong intermolecular attractions, such as hydrogen bonds in alcohols, tend to have low volatility. They need more energy to break their bonds and turn into vapor.


• Ethers, on the other hand, lack these strong hydrogen bonds even though they have dipole-dipole interactions due to their polar nature. This lack of strong hydrogen bonding results in ethers being more volatile than alcohols.

Because ethers vaporize more easily, they often have lower boiling points compared to alcohols with a similar molecular weight. Understanding volatility can help in various scientific applications like solvent selection in chemical reactions.

Dipolar Character of Ethers

Ethers are interesting compounds mainly because of their polar nature. They are composed of an oxygen atom bonded to two alkyl or aryl groups, and this oxygen atom lends them a dipolar character. What this means is that there is a negative pole near the oxygen and positive poles near the carbon atoms.

• Despite this polarity, ethers do not exhibit the same hydrogen bonding seen in alcohols because the hydrogen atoms in ethers are not bonded directly to an oxygen or nitrogen atom, which is required for hydrogen bonding.


• Even though ethers are polar, they do not have the strong intermolecular forces found in alcohols, which limits their boiling point elevation compared to alcohols.

Thus, the dipolar character of ethers contributes to their physical properties, such as solubility and volatility, but it does not lead to the same extent of intermolecular attraction found in alcohols.