Chapter 18: Problem 132
What feature must a molecule or an ion have in order to act as a Lewis base? A Lewis acid? Explain the roles of these features.
Short Answer
Expert verified
A Lewis base must have a lone pair of electrons to donate. A Lewis acid must have an empty orbital to accept electron pairs.
Step by step solution
01
Understanding Lewis Base
A Lewis base is a substance that can donate a pair of electrons. This ability to donate electrons is due to the presence of a lone electron pair on an atom within the molecule or ion.
02
Identifying Lone Pairs
Look for molecules or ions with atoms that possess lone pairs of electrons. Common examples include water (H₂O), ammonia (NH₃), and hydroxide ions (OH⁻). These lone pairs are typically located on elements like nitrogen, oxygen, and sulfur.
03
Understanding Lewis Acid
A Lewis acid is a substance that can accept a pair of electrons. This acceptance of electron pairs happens because the Lewis acid has an empty orbital that can accommodate a pair of electrons.
04
Identifying Empty Orbitals
Identify molecules or ions with atoms that have empty orbitals. Common examples include BF₃, AlCl₃, and metal cations like Fe³⁺, which all can accept electron pairs due to their empty orbitals.
05
Roles of Features
The lone pairs on Lewis bases allow them to donate electrons and form bonds with Lewis acids. Conversely, the empty orbitals on Lewis acids enable them to accept electron pairs from Lewis bases, facilitating bond formation.
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with Vaia!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Lewis base
In chemistry, a Lewis base is any substance that can donate a pair of electrons. This typically happens because there is an atom within the molecule or ion that has a lone pair of electrons. Such a lone pair is not shared with any other atoms, making it available for donation.
For example, substances like water (H₂O), ammonia (NH₃), and hydroxide ions (OH⁻) have lone pairs of electrons on their atoms. In water, the oxygen atom has lone pairs, in ammonia, the nitrogen atom has lone pairs, and in hydroxide ions, the oxygen atom also has lone pairs. These lone pairs are able to be donated to another species, which makes these substances Lewis bases.
For example, substances like water (H₂O), ammonia (NH₃), and hydroxide ions (OH⁻) have lone pairs of electrons on their atoms. In water, the oxygen atom has lone pairs, in ammonia, the nitrogen atom has lone pairs, and in hydroxide ions, the oxygen atom also has lone pairs. These lone pairs are able to be donated to another species, which makes these substances Lewis bases.
Electron pair donation
Electron pair donation is the fundamental characteristic of a Lewis base. Essentially, this means that a Lewis base has the capacity to share a lone pair of electrons with another chemical species, specifically a Lewis acid.
This sharing creates a coordinate bond, also known as a dative bond, where both electrons originate from the Lewis base. The ability to donate an electron pair is crucial because it enables the Lewis base to form new chemical bonds and participate in various chemical reactions.
In summary, for a molecule or ion to act as a Lewis base, it must have lone pairs of electrons that it can donate. This donation capability allows for the formation of new bonds, playing a critical role in chemical interactions.
This sharing creates a coordinate bond, also known as a dative bond, where both electrons originate from the Lewis base. The ability to donate an electron pair is crucial because it enables the Lewis base to form new chemical bonds and participate in various chemical reactions.
In summary, for a molecule or ion to act as a Lewis base, it must have lone pairs of electrons that it can donate. This donation capability allows for the formation of new bonds, playing a critical role in chemical interactions.
Lewis acid
A Lewis acid is a substance that can accept a pair of electrons. This occurs because a Lewis acid possesses empty orbitals that can accommodate electron pairs.
Common examples of Lewis acids include boron trifluoride (BF₃), aluminum chloride (AlCl₃), and metal cations such as Fe³⁺. These substances can accept electron pairs because their atoms have empty orbitals. For instance, in BF₃, the boron atom has an empty orbital that can accept an electron pair from a Lewis base.
In summary, Lewis acids are characterized by their ability to accept electron pairs due to the presence of empty orbitals, making them essential participants in the formation of new chemical bonds.
Common examples of Lewis acids include boron trifluoride (BF₃), aluminum chloride (AlCl₃), and metal cations such as Fe³⁺. These substances can accept electron pairs because their atoms have empty orbitals. For instance, in BF₃, the boron atom has an empty orbital that can accept an electron pair from a Lewis base.
In summary, Lewis acids are characterized by their ability to accept electron pairs due to the presence of empty orbitals, making them essential participants in the formation of new chemical bonds.
Empty orbital
An empty orbital in an atom or ion is crucial for it to act as a Lewis acid. An empty orbital is a space within an atom that does not contain electrons but is capable of accepting an electron pair.
When a Lewis base donates its electron pair, this electron pair is then accepted into the empty orbital of the Lewis acid. This results in the formation of a coordinate covalent bond. The presence of these empty orbitals is what allows Lewis acids to participate in chemical bonding and reactions.
Therefore, identifying these empty orbitals in molecules or ions is key to determining whether or not they can function as Lewis acids in various chemical processes.
When a Lewis base donates its electron pair, this electron pair is then accepted into the empty orbital of the Lewis acid. This results in the formation of a coordinate covalent bond. The presence of these empty orbitals is what allows Lewis acids to participate in chemical bonding and reactions.
Therefore, identifying these empty orbitals in molecules or ions is key to determining whether or not they can function as Lewis acids in various chemical processes.
Bond formation
Bond formation between a Lewis base and a Lewis acid involves the donation and acceptance of an electron pair. The process begins when a Lewis base donates a pair of electrons to a Lewis acid, which has an empty orbital ready to accept them.
Upon donation, the electron pair from the Lewis base fills the empty orbital in the Lewis acid. This interaction leads to the formation of a coordinate covalent bond, where both electrons in the bond come from the Lewis base.
This mechanism of bond formation is fundamental in many chemical reactions, especially in the formation of complex molecules and coordination compounds. Understanding this electron pair interaction and bond formation is essential in the study of chemistry, as it explains how different substances can interact and form stable compounds.
Upon donation, the electron pair from the Lewis base fills the empty orbital in the Lewis acid. This interaction leads to the formation of a coordinate covalent bond, where both electrons in the bond come from the Lewis base.
This mechanism of bond formation is fundamental in many chemical reactions, especially in the formation of complex molecules and coordination compounds. Understanding this electron pair interaction and bond formation is essential in the study of chemistry, as it explains how different substances can interact and form stable compounds.
