Using Drago and Waylands E and C equation, calculate the enthalpy of adduct formation for the following reactions. Explain the trends in terms of the electrostatic and covalent contributions. Note: See the tables on the last page for E and C values.

a) BF3 reacting with NH3, NH2(CH3), NH(CH3)2, and N(CH3)3

b) Pyridine reacting with B(CH3)3, Al(CH3)3, and Ga(CH3)3