Question

An objectionable component of smog is acetyl peroxide, which has the following skeleton structure. CC(=O)OCC(C)O (a) Draw the Lewis structure of this compound. (b) Write the bond angles indicated by the numbered angles.

Short answer

Answer: The bond angle for the C=O group is approximately 120 degrees, while the bond angle for the O-C(=O)-O group is approximately 109.5 degrees.

Step-by-step solution

Draw the Lewis structure

To draw the Lewis structure of acetyl peroxide, we will first convert the given skeleton structure into an extended structure, and then add electron pairs to fulfill the octet rule for each atom. Skeleton structure: CC(=O)OCC(C)O Extended structure: CH3-C(=O)-O-C-CH3-O Now, let's complete the octet for each atom by adding lone pairs and/or making double bonds: Lewis structure: CH3-C(=O)-O-C(=O)-CH3-O Following the octet rule, each atom has its necessary total number of electrons. For example, oxygen atoms have two lone pairs (four electrons), in addition to their bonds.

Determine the hybridization

To determine the bond angles, we need to identify the hybridization of the central atoms (carbon and oxygen) in the molecule. For the carbon atom that is part of the double bond (C=O): - It forms three sigma bonds (one to CH3, one to O in the O-C(=O)-O, and one to O in C=O) and has no lone pairs on it. - This configuration corresponds to an sp2 hybridization. For the oxygen atom in the central O-C(=O)-O group: - It forms two sigma bonds (one to the carbon atom in C=O and one to the carbon atom in CH3-C(=O)) and has two lone pairs. - This configuration corresponds to an sp3 hybridization.

Calculate the bond angles

Based on the hybridizations found in step 2, we can determine the bond angles: sp2 hybridization (C=O): - The bond angles in an sp2 hybridized molecule are approximately 120 degrees. sp3 hybridization (O-C(=O)-O): - The bond angles in an sp3 hybridized molecule are approximately 109.5 degrees. So, the numbered bond angles in the acetyl peroxide molecule are as follows: 1. 120 degrees (C=O with sp2 hybridization) 2. 109.5 degrees (O-C(=O)-O with sp3 hybridization)