## Chemistry and Chemical Reactivity (9th Edition)

a,b) Carbons in the aromatic ring are $sp^2$ hybridized because they make a double bond each, thus angle A is 120°. The other carbons and the nitrogen are $sp^3$ hybridized because they make single bonds only, thus angles B and C are approximately 109°. c) There are 25 $\sigma$ bonds and 3 $\pi$ bonds. d) This molecule is polar because it has asymmetrical polar bonds (CN and NH). e) The proton attaches itself to the nitrogen because it's the most electronegative atom in the molecule and has a lone electron pair, both displayed in the potential surface by the red spot around it.