Question

Which of the following has the maximum extent of hydrogen bonding? (a) ethyl amine (b) ammonia (c) ethyl alcohol (d) diethyl ether

Short answer

Ammonia ( ext{NH}_3) has the maximum extent of hydrogen bonding.

Step-by-step solution

Understanding Hydrogen Bonding

Hydrogen bonding occurs when hydrogen is directly bonded to highly electronegative atoms like nitrogen (N), oxygen (O), or fluorine (F). The strength and extent of hydrogen bonding depend on the number of hydrogen atoms available for bonding and the electronegativity of the atoms they are bonded to.

Examining Each Compound

We will analyze the compounds one by one: - Ethyl amine ( ext{C}_2 ext{H}_5 ext{NH}_2): It has a nitrogen atom which can participate in hydrogen bonding. - Ammonia ( ext{NH}_3): Has three hydrogen atoms bonded to nitrogen, offering multiple sites for hydrogen bonding. - Ethyl alcohol ( ext{C}_2 ext{H}_5 ext{OH}): Contains an ext{OH} group, where oxygen is highly electronegative, supporting hydrogen bonding. - Diethyl ether ( ext{C}_4 ext{H}_{10} ext{O}): Oxygen is present, but there aren't hydrogen atoms bonded to it directly, limiting hydrogen bonding potential.

Comparison of Hydrogen Bonding Capabilities

- In ethyl amine, only the hydrogen(s) attached to nitrogen has significant hydrogen bonding capability. - Ammonia, with its three hydrogen atoms directly bonded to nitrogen, can form numerous hydrogen bonds. - Ethyl alcohol has a strong hydrogen bond capability through its hydroxyl group. - Diethyl ether, lacking direct hydrogen to oxygen bonding, has limited hydrogen bonding ability.

Evaluating Based on Extent of Hydrogen Bonding

Ammonia's structure allows it to form extensive hydrogen bonding because each of its three hydrogen atoms can bond with other electronegative atoms, making it more pronounced than the others. Ethyl alcohol also has strong hydrogen bonds but cannot match the extent present in ammonia.

Key concepts

Electronegativity

Electronegativity plays a crucial role in hydrogen bonding. It refers to the ability of an atom to attract electrons towards itself in a chemical bond. The higher the electronegativity, the stronger the pull on electrons. This is especially important for forming hydrogen bonds, as only highly electronegative atoms like nitrogen (N), oxygen (O), or fluorine (F) strongly attract hydrogen atoms.
- Nitrogen in ammonia and ethyl amine - Oxygen in ethyl alcohol and diethyl ether
Understanding the electronegativity of these atoms helps explain why some molecules can form stronger hydrogen bonds than others. For instance, oxygen and nitrogen have electronegativity values of 3.44 and 3.04 respectively, which enable them to create significant bonding interactions with hydrogen.

Hydrogen Bonding in Ammonia

Hydrogen bonding in ammonia is a fascinating process that occurs due to the presence of nitrogen. Ammonia (NH extsubscript{3}) consists of a nitrogen atom bonded to three hydrogen atoms, allowing for extensive hydrogen bonding.
- Each hydrogen atoms offers a site for hydrogen bonding. - Nitrogen’s high electronegativity attracts electron density from the hydrogen atoms, polarizing the N-H bonds.
As a result, each hydrogen in ammonia can participate in bonding with other electronegative atoms in proximity, allowing ammonia molecules to bond with as many as three hydrogen bonds simultaneously. This extensive bonding capability gives ammonia significant intermolecular attractions, affecting its physical properties like boiling point and solubility.

Hydrogen Bonding in Alcohols

Alcohols, like ethyl alcohol (C extsubscript{2}H extsubscript{5}OH), are another excellent example of hydrogen bonding, primarily through their hydroxyl (-OH) group.
- The oxygen atom in the hydroxyl group is highly electronegative. - This leads to a strong dipole between the oxygen and hydrogen within the
This polar OH bond provides a site for robust hydrogen bonding, as the partially positive hydrogen can attract other nearby electronegative atoms. As a result, alcohols tend to have higher boiling points and are typically more soluble in water compared to similarly sized hydrocarbons, thanks to these strong intermolecular forces.

Nitrogen and Hydrogen Bonds

The interaction between nitrogen and hydrogen is foundational for understanding hydrogen bonds in compounds like ethyl amine and ammonia.
- The presence of nitrogen increases the potential for strong hydrogen bonds. - In ammonia, nitrogen shares bonds with three hydrogen atoms, maximizing bonding potential.
In ethyl amine, the nitrogen atom bonded to hydrogen also supports hydrogen bonding; however, the presence of additional hydrocarbon parts can influence the extent to which these bonds are formed. Overall, the interaction between nitrogen and hydrogen significantly impacts a molecule's ability to form hydrogen bonds and influences the compound's physical and chemical properties.