Problem 5 - Chemistry A Guided Inquiry

Question

How do the calculated bond orders for benzene compare to the bond orders predicted by the Lewis structure?

Step-by-Step Solution

Answer

The calculated bond order of benzene is 'one-and-a-half', matching the bond order predicted by the Lewis structure, which captures the intrinsic resonance of the benzene molecule.

Step 1: Understanding Benzene Structure

Benzene is a cyclic hydrocarbon with a chemical formula C6H6. Each carbon atom in the molecule is equidistant from each other, and they are all sp2 hybridized. There are 3 single & 3 double bonds which, according to Lewis structure, switch places every time, creating resonance.

Step 2: Calculation of Bond Order

Typically, bond order is calculated as the number of bonds between atoms. For benzene, you could count each bond as either single or double. Thus, considering resonance, each bond in benzene is something in between - neither single nor double. Instead, it is often described as 'one-and-a-half'.

Step 3: Comparing Calculated and Predicted Bond Orders

Comparing the calculation and Lewis structure prediction, they should match as the Lewis structure correctly predicts the bond order to be 'one-and-a-half' due to its depiction of alternating double and single bonds for benzene, capturing the resonance structure.