IB skill practice

Explain resonance and formal charge in Lewis models

Paper 1, Paper 2 5 marks Difficulty 4

Bond order from resonance forms

A resonance model in a Melbourne spectroscopy practical spreads one extra pi bond equally over 3 equivalent bonds. State the extra pi-bond contribution to each bond. Enter the answer and choose the interpretation that matches the HL chemistry evidence.

Worked practice: chemistry evidence and answer

Use the chemical evidence first, then enter the result and interpretation that match it.