The substances E-OH and NH3 (or R2-N-H) are potentially capable of acting either as acids (proton donors) or as bases (proton acceptors) because they both have an atom bearing nonbonding pairs (O or N), and they both have a hydrogen atom bonded to a more electronegative element.

the prominent mode of reaction for E-OH is donation of a proton.

the prominent mode of reaction for NH3 (R2NH) is accepting a proton.
In water
Dr Sheila Woodgate
© The University of Auckland 2002