Problem 66 - A Complete Resource Book in Chemistry for JEE Main

Question

The bonds present in \(\mathrm{N}_{2} \mathrm{O}_{5}\) are (a) only ionic (b) covalent and coordinate (c) only covalent (d) covalent and ionic

Step-by-Step Solution

Answer

The bonds in \(\text{N}_2\text{O}_5\) are covalent and coordinate (Option b).

Step 1: Identify the Bond Types

In general, the bonds within a molecule like \(\text{N}_2\text{O}_5\) are typically covalent, as they involve non-metal atoms. Non-metals usually share electrons to fill their valence shells, forming covalent bonds.

Step 2: Consider Coordinate Bonds

Coordinate bonds occur when one atom donates both electrons for a bond. In \(\text{N}_2\text{O}_5\), there is a nitrogen-oxygen bond that might be considered a coordinate bond because nitrogen can donate a lone pair to oxygen in some resonance forms. This suggests that the molecule could have both normal covalent and coordinate covalent bonds.

Step 3: Evaluate Ionic Bond Potential

Ionic bonds generally form between metals and nonmetals with large differences in electronegativity. Since \(\text{N}_2\text{O}_5\)'s atoms are all non-metal, it is unlikely to have ionic bonds.

Step 4: Conclude Based on Potential Bonds

Based on the identified bond types, \(\text{N}_2\text{O}_5\) includes covalent bonds predominantly formed by sharing electrons, and potentially coordinate covalent bonds where atoms might share electron pairs differently. There is no clear mechanism for ionic bonding here.

Key Concepts

Coordinate Bonding

Coordinate bonding, also known as a dative covalent bond, happens when both electrons in a bond come from the same atom. This type of bond typically occurs when one atom has a lone pair of electrons and can share them with another atom that needs extra electrons to achieve stability. In molecules like \(\text{N}_2\text{O}_5\), coordinate bonds may form between nitrogen and oxygen atoms. Oxygen often requires additional electrons to complete its octet. Nitrogen, having a lone pair, might donate these electrons to oxygen in certain structures.

Key characteristics of coordinate bonds include:

• One atom donates both electrons used to form the bond.
• The bonded atoms are typically nonmetals.
• They form between atoms with available lone electron pairs and those deficient in electrons.

Understanding coordinate bonds is crucial for grasping the molecular structure, as they can subtly alter the understanding of a molecule's electron distribution and resonance forms.

Molecular Structure

Molecular structure refers to the 3D arrangement of atoms within a molecule. It determines the physical and chemical properties of a compound. For \(\text{N}_2\text{O}_5\), understanding its molecular structure requires considering not just the individual covalent bonds, but also any coordinate bonds that influence electron cloud shapes and resonance states.

Key aspects of molecular structures:

• The specific angles and distances between atoms using geometrical measurement.
• The influence of electron repulsion shapes and how electron pairs organize in space.
• The concept of resonance, which explains molecules with multiple possible configurations, like \(\text{N}_2\text{O}_5\), thus changing our perspective on its molecular setup.

Molecular structure not only depicts the skeletal arrangement but also reveals electron density distribution which impacts reactivity and interactions with other molecules.

Chemical Bonding

Chemical bonding encompasses the forces that hold atoms together in compounds. There are various bond types including covalent, ionic, and metallic, each with unique characteristics and formation processes. Covalent bonding, shared between non-metal atoms, is most common in \(\text{N}_2\text{O}_5\). Here atoms share electron pairs to achieve full valence shells and improve stability.

Features of chemical bonds include:

• Covalent bonds involve sharing electrons between atoms, essential for molecules like \(\text{N}_2\text{O}_5\).
• Coordinate covalent bonds occur when one atom provides both electrons in the shared pair, enriching the complexity of molecular formation.
• Ionic bonds, although not present in \(\text{N}_2\text{O}_5\), involve transfer of electrons, resulting in charged ions that strongly attract each other.

Grasping these bond types is critical to understanding molecular synthesis and behavior, dictating how molecules react and interact in various chemical contexts.