Label the acid-base and conjugate acid-base pairs? HCO3–(aq)+ H2O(l) —->H2CO3(aq)+ OH–(aq)

##HCO_3^(-) + H_2O -> H_2CO_3 + OH^-##
##Base + Acid -> Conj A + Conj B##
On the reactant side of the equation the water (##H_2O##) is the Acid as it is the hydrogen ion donor to the bicarbonate (##HCO_3^-##) which is the Base as it receives the hydrogen ion..
On the product side the Carbonic Acid (##H_2CO_3##) is the Conjugate Acid as it is the hydrogen donor to the Conjugate Base (##OH^-##) as it receives the hydrogen ion.
##HCO_3^(-) -> H_2CO_3 ##
##Base -> Conj A##
The Carbonic Acid (##H_2CO_3##) is the Conjugate Acid pair to the Base bicarbonate (##HCO_3^-##) .
##H_2O -> OH^-##
##Acid -> Conj B##
The Hydroxide (##OH^-##) is the Conjugate Base pair to the Water (H_2O).
I hope this was helpful.
SMARTERTEACHER