Solution: There are only four constitutional isomers with molecular formula  C4H9NO2 that contain a nitro group (–NO2). Three of these isomers have similar pKa values, while the fourth isomer has a much higher

There are only four constitutional isomers with molecular formula  C₄H₉NO₂ that contain a nitro group (–NO₂). Three of these isomers have similar pKa values, while the fourth isomer has a much higher pKa value. Draw all four isomers and identify which one has the higher pKa. Explain your choice.