Skip to main content
Ch.16 - Aqueous Equilibria: Acids & Bases
Chapter 16, Problem 45

Look at the electron-dot structures of the following molecules and ions: (b) Which can behave as a Lewis acid? Which can behave as a Lewis base?

Verified step by step guidance
1
Identify the electron-dot structures of the given molecules and ions. Electron-dot structures, also known as Lewis structures, show the valence electrons around atoms.
Understand the definition of a Lewis acid and a Lewis base. A Lewis acid is an electron pair acceptor, typically an entity with an incomplete octet or a positive charge. A Lewis base is an electron pair donor, usually a species with lone pairs of electrons that are not involved in bonding.
Examine each molecule or ion to determine if there are any atoms with incomplete octets or positive charges, which would indicate potential to act as a Lewis acid.
Look for atoms in the molecules or ions that have lone pairs of electrons. These are potential sites for the molecule or ion to act as a Lewis base by donating these lone pairs.
Classify each molecule or ion based on the presence of electron-deficient sites or lone pairs, determining which can act as Lewis acids and which can act as Lewis bases.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Lewis Acids and Bases

Lewis acids are substances that can accept an electron pair, while Lewis bases are those that can donate an electron pair. This definition expands the concept of acids and bases beyond protons, focusing instead on electron pair interactions. Understanding this distinction is crucial for identifying the behavior of molecules and ions in chemical reactions.
Recommended video:
Guided course
05:04
Lewis Acids and Bases

Electron-Dot Structures

Electron-dot structures, or Lewis structures, visually represent the valence electrons of atoms within a molecule or ion. They help in predicting how atoms bond and interact with each other, as well as in identifying lone pairs and formal charges. Analyzing these structures is essential for determining which species can act as Lewis acids or bases.
Recommended video:
Guided course
04:28
Lewis Dot Structures: Ions

Molecular Geometry and Hybridization

The geometry and hybridization of a molecule influence its reactivity and ability to act as a Lewis acid or base. For instance, molecules with empty orbitals can accept electron pairs, making them Lewis acids, while those with lone pairs can donate electrons, acting as Lewis bases. Understanding these spatial arrangements is key to predicting chemical behavior.
Recommended video:
Guided course
03:06
Hybridization and Electron Geometry