Hw Help 6A.1

[Luke Schwuchow 14A]

Hello! I was wondering when we write out the conjugate acids, and we write out the lewis structure beforehand, how do we know what reacts with what? For example, in CH3NH2 + H2O, how come the nitrogen bonds with a hydrogen and not the oxygen in H2O? Does it have to do with formal charges or electronegativity?

[Alex Yeghikian 1C]

A base will accept a proton (H⁺) to form its conjugate acid. For this question it's a matter of recognizing that to form a conjugate acid you add a hydrogen to the base, and to form a conjugate base you remove a hydrogen from the acid. For that particular example, it would be helpful to identify the NH₂ functional group in the molecule, which will become NH₃⁺ in the conjugate acid. I don't believe an acid-base reaction can involve bonding to the oxygen and forming H₂.