Question

Give the number and type of hybrid orbital that forms when each set of atomic orbitals mixes: (a) one \(p\) and one \(s\) (b) three \(p,\) one \(d,\) and one \(s\)

Short answer

(a) sp (two sp hybrid orbitals); (b) sp³d (five sp³d hybrid orbitals)

Step-by-step solution

Identify Atomic Orbitals Mixing for Part (a)

Consider the orbitals given: one 2p orbital and one 2s orbital.

Determine the Type of Hybridization for Part (a)

When one 2p orbital and one 2s orbital mix, they form two sp hybrid orbitals.

Identify Atomic Orbitals Mixing for Part (b)

Consider the orbitals given: three 3p orbitals, one 3d orbital, and one 3s orbital.

Determine the Type of Hybridization for Part (b)

When three 3p orbitals, one 3d orbital, and one 3s orbital mix, they form five sp³d hybrid orbitals.

Key concepts

sp hybridization

In sp hybridization, an atomic orbital undergoes mixing between one s orbital and one p orbital. This process is vital for understanding the geometry of molecules. When sp hybridization occurs, it results in the formation of two sp hybrid orbitals. Each of these orbitals has equal energy and is oriented 180 degrees apart, forming a linear molecular shape. This type of hybridization is commonly observed in molecules such as acetylene (C₂H₂), where each carbon atom uses sp hybrid orbitals to form a triple bond with another carbon.

sp³d hybridization

The sp³d hybridization involves the mixing of one s orbital, three p orbitals, and one d orbital. This hybridization results in the creation of five sp³d hybrid orbitals. These orbitals are oriented in a trigonal bipyramidal geometry. In such molecules, three of the sp³d orbitals lie in a plane at 120-degree angles to one another, while the other two orbitals are placed perpendicular to this plane. This hybridization is observed in molecules like phosphorus pentachloride (PCl₅). The diverse angles ensure that the electrons are as far apart as possible, minimizing repulsion and stabilizing the molecule.

hybrid orbitals

Hybrid orbitals are the result of combining atomic orbitals within an atom to form new orbitals that influence bonding. These new orbitals have distinct shapes and energies compared to the original atomic orbitals. The main types of hybrid orbitals include sp, sp², sp³, sp³d, and sp³d². Each type corresponds to a different geometrical arrangement of bonds around the central atom. Understanding hybrid orbitals is crucial for predicting the geometry, bonding, and properties of molecules. For instance, sp² hybrid orbitals form a trigonal planar shape, sp³ forms a tetrahedral shape, and so on. Recognizing these patterns helps in visualizing molecular structures and predicting their reactivity.