Question

Differentiate between covalent and coordinate bond.

Short answer

Covalent bonds and Coordinate bonds are types of chemical bonding involving electron sharing between atoms. The key difference is the source of electrons; in covalent bonding, electrons are mutually shared by both atoms to achieve stability whilst in coordinate bonding, both electrons are donated by a single atom (donor). They, however, behave similarly once the bond has been formed.

Step-by-step solution

Understanding Covalent Bond

A Covalent bond is a type of chemical bond where two atoms are connected to each other by the sharing of two or more electrons. An atom's stability is determined by its electronic configuration, and atoms tend to react to obtain a full set of electrons, normally eight, in their outermost shell. This process could result in covalent bonding. Here, both atoms share the electrons mutually to complete their respective octets.

Understanding Coordinate Bond

A coordinate bond, also known as a dative bond, involves the sharing of a pair of electrons between two atoms; however, in this case, both electrons are donated by only one atom. The atom which donates both electrons is called the donor (a Lewis base), and the atom which accepts the pair of electrons is called the acceptor (a Lewis acid). Coordinate bonds are typically represented by an arrow pointing towards the acceptor atom.

Differentiating between Covalent and Coordinate Bond

In covalent bonds, the shared electrons originate from each of the atoms involved in the bonding, resulting in a mutual sharing. In contrast, in the formation of a coordinate bond, the shared electrons are donated solely by one atom (the donor atom). Another difference is that, once a coordinate bond has been formed, it cannot be distinguished from other covalent bonds; it behaves as a normal covalent bond does. Both types of bonds can occur together in several molecules.

Key concepts

Covalent Bond

Covalent bonds are a fundamental type of chemical bond critical for many substances we encounter daily. These bonds occur when two atoms share one or more pairs of electrons. This sharing allows each atom to acquire the electron configuration of a noble gas, leading them to a more stable state. Typically, the aim is to achieve an octet, meaning eight electrons in the outer shell. This is particularly the case with elements like carbon, nitrogen, and oxygen.

• Atoms involved in covalent bonding are unable to donate or accept electrons completely, so they prefer to share them.
• The strength of a covalent bond depends on the overlap of atomic orbitals; the greater the overlap, the stronger the bond.
• Covalent bonds can be single, double, or triple, indicating the number of shared electron pairs.

These bonds play a key role in forming complex molecules like proteins and DNA, representing how versatile and vital covalent bonds are in life.

Coordinate Bond

A coordinate bond, sometimes known as a dative covalent bond, is a unique type of bond distinguished by the manner of electron sharing. In a coordinate bond, both electrons in the shared pair come from the same atom. This atom is known as the donor. Meanwhile, the atom receiving the electron pair is called the acceptor. This forms a link similar to a traditional covalent bond.

• The donor is often a Lewis base, as it has lone pairs of electrons to donate.
• The acceptor, a Lewis acid, is typically electron-deficient and can accommodate more electrons.
• Coordinate bonds are usually depicted with an arrow pointing from the donor to the acceptor.

Even though the origins of the bond involve a single donor, once formed, the bond becomes indistinguishable from any other covalent bond in terms of properties and behavior.

Electron Sharing

At the heart of both covalent and coordinate bonds is the concept of electron sharing, which is a fundamental principle in chemical bonding. Electron sharing involves atoms gaining stability by sharing their outermost electrons. This sharing process allows atoms to achieve a full outer shell configuration, crucial for stability.

• In covalent bonds, electron sharing is mutual and equally contributed by the bonded atoms.
• In coordinate bonds, one atom fully provides both electrons for the shared pair, highlighting a donor-acceptor relationship.
• Electron sharing can result in different bond strengths and lengths, influenced by the type and number of shared electrons.

Understanding electron sharing helps explain not only how individual bonds form but also how these contribute to the larger structure and function of molecules. It’s the basis of forming stable molecular compounds.

Lewis Base and Acid

The concepts of Lewis bases and acids are integral to understanding coordinate bonds. A Lewis base is a substance that can donate an electron pair, making it a key player in forming coordinate bonds. Conversely, a Lewis acid is an entity that can accept an electron pair. This duality underpins many reactions and interactions in chemistry.

• Lewis bases are typically rich in electrons with lone pairs, like ammonia ( \( \text{NH}_3 \)) or water ( \( \text{H}_2\text{O} \)).
• Lewis acids, in contrast, are electron-deficient and are often metal ions or compounds like boron trifluoride ( \( \text{BF}_3 \)).
• The interaction between a Lewis base and Lewis acid facilitates the formation of a coordinate bond.

Recognizing Lewis bases and acids allows chemists to predict and design complex molecular structures and reactions, revealing the reactive potential of molecules.