Question

What is the hybridization of each carbon atom in acetonitrile (Prob\(\operatorname{lem} 1-26) ?\)

Short answer

Methyl carbon is sp³ hybridized; nitrile carbon is sp hybridized.

Step-by-step solution

Identify the Structure of Acetonitrile

Acetonitrile has the molecular formula CH₃CN. It consists of a methyl group (CH₃-) bonded to a nitrile group (-CN). The structure can be drawn as CH₃−C≡N, where the nitrile group contains a triple bond between the carbon and nitrogen atoms.

Determine the Hybridization of the Methyl Carbon

The methyl carbon (CH₃) is bonded to three hydrogen atoms and one carbon atom from the nitrile group. Therefore, it makes four single bonds. The hybridization of a carbon atom with four single bonds is sp³.

Determine the Hybridization of the Nitrile Carbon

The nitrile carbon (C) is bonded to one carbon atom from the methyl group and has a triple bond with the nitrogen atom. A carbon atom that forms a triple bond and one single bond is sp hybridized. Thus, the nitrile carbon is sp hybridized.

Conclusion: Analyze Hybridization States

The methyl carbon in acetonitrile is sp³ hybridized because it forms four sigma bonds, while the nitrile carbon is sp hybridized since it forms one sigma bond and two pi bonds.

Key concepts

Acetonitrile

Acetonitrile is a simple organic compound with the chemical formula CH₃CN. It can be found in various forms but is commonly experienced as a colorless liquid.
One notable aspect of acetonitrile is its dipole moment due to the different electronegativities between carbon and nitrogen.

• It consists of a methyl group (CH₃-) bonded to a nitrile group (-CN).
• The key structural feature is the triple bond between the carbon and nitrogen atoms in the nitrile group.

Acetonitrile is versatile and used in industries such as the manufacturing of pharmaceuticals and in chemical analysis as a solvent.
Understanding its structure, especially bonds and hybridization, is crucial for predicting its reactivity and interactions.

sp³ hybridization

In organic chemistry, sp³ hybridization plays a fundamental role. It describes how carbon's atomic orbitals mix to form new hybrid orbitals.
For a carbon atom with sp³ hybridization, there are significant changes from the pure atomic orbitals.

• The carbon atom uses one s orbital and three p orbitals to form four equivalent sp³ hybrid orbitals.
• Each of these hybrid orbitals can form a sigma bond, which is the case for the methyl carbon in acetonitrile.

As such, carbon with sp³ hybridization typically forms a tetrahedral geometry. By having four sigma bonds, an sp³ hybridized carbon achieves a stable, full valence shell configuration.
This understanding helps to illustrate how atoms connect and form the molecular backbone in many compounds.

sp hybridization

The concept of sp hybridization helps describe how certain carbon atoms bond, especially those with triple bonds. This type of hybridization is particularly notable in molecules with linear geometry.
When carbon undergoes sp hybridization:

• The carbon uses one s orbital and one p orbital, forming two sp hybrid orbitals.
• The remaining two p orbitals are left unhybridized and are crucial in forming pi bonds.

This hybridization allows for the triple bond seen in the behavior of the nitrile group of acetonitrile.
In this scenario, one sigma bond forms between carbon and nitrogen from overlapping sp orbitals, while two pi bonds result from the side-by-side overlap of unhybridized p orbitals. This setup grants a strong bond and explains structural stability seen in nitrile compounds.

Carbon hybridization

Carbon hybridization is a central concept in organic chemistry. It explains how carbon forms different types of covalent bonds. The hybridization state of a carbon atom offers insights into its geometry and bonding properties.
Carbon atoms can adapt three prominent hybridization states:

• sp³ hybridization is seen in carbon atoms with four single sigma bonds.
• sp² hybridization occurs in carbon atoms forming one double bond and two single bonds.
• Lastly, sp hybridization is important in carbon atoms involved in one triple bond or two double bonds.

Recognizing these states aids in predicting molecular shapes and understanding the reactivity of substances.
For example, in acetonitrile, the diverse hybridization of carbon atoms illustrates the principle that organic molecules can hold varying quantum configurations within their lattice.