Which is not a conjugate acid-base pair?
a) H3O+ and H2O
b) H2O and OH-
c) NH3 and NH2--
d) NH4+ and NH3
e) HNO2 and H2O
c) NH3 and NH2--
This is not a conjugate acid-base pair because NH2-- is not a valid species.
are you sure?
I apologize for the incorrect response. I made an error.
The correct answer is e) HNO2 and H2O.
HNO2 is a weak acid and H2O is not its conjugate base.