Question

1 (a) UsingVSEPR, predict each $\ma… # Following is a structural formula of benzene, \(\mathrm{C}_{6} \mathrm{H}_{6}\) which we study in Chapter 21 . c1ccccc#1 (a) UsingVSEPR, predict each \(\mathrm{H}-\mathrm{C}-\mathrm{C}\) and \(\mathrm{C}-\mathrm{C}-\mathrm{C}\) bond angle in benzene. (b) State the hybridization of each carbon in benzene. (c) Predict the shape of a benzene molecule. (d) Draw important resonance contributing structures. Copyright 2018 Cengage Learning. All Rights Reserved. May not be copicd, scanned, or duplicatedi, in whole or in part. WCN 02 .

Short answer

Question: Predict the H-C-C and C-C-C bond angles, state the hybridization of each carbon atom in benzene, predict the shape of the benzene molecule, and draw important resonance contributing structures. Answer: The H-C-C and C-C-C bond angles in benzene are 120 degrees. Each carbon atom in benzene is sp2 hybridized. The shape of the benzene molecule is a planar hexagonal ring. Benzene has two significant resonance structures with flipped positions of the double bonds, contributing to its overall stability and unique properties.

Step-by-step solution

Visualize the benzene molecule

First, we need to visualize the benzene molecule, which is a planar, hexagonal ring with alternating single and double carbon-carbon bonds, and a hydrogen atom attached to each carbon atom.

Predict the bond angles

Using VSEPR theory, we know that the bond angles are determined by the repulsion between bonding and non-bonding electron pairs around the central atom. (a) In benzene, each carbon atom is bonded to two other carbon atoms and one hydrogen atom. There are no lone pairs of electrons present on the carbon atoms. Since the molecule is planar and hexagonal, the angle between each C-C-C and H-C-C bond is 120 degrees.

Determine the hybridization of each carbon atom

(b) To determine the hybridization of each carbon atom in benzene, consider the number of sigma bonds and lone pairs on each carbon atom. Each carbon atom has three sigma bonds (one with a hydrogen atom and two with neighboring carbon atoms). There are no lone pairs of electrons. Therefore, each carbon atom in benzene is sp2 hybridized.

Predict the shape of the benzene molecule

(c) Since the benzene molecule is planar and has a hexagonal ring of carbon atoms with alternating single and double bonds and a hydrogen atom attached to each carbon atom, its shape is described as a planar hexagonal ring.

Draw important resonance contributing structures

(d) Benzene has two significant resonance structures, in which the positions of the double bonds are flipped. You can visualize these structures by drawing two hexagonal rings with alternating single and double bonds and then swapping the positions of the double bonds between the two structures. This resonance stabilization contributes to benzene's overall stability and unique properties.