In the following reaction,

$\underset{\text{ Acid }}{{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}}+\underset{\mathrm{X}}{{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}}\underset{ }{\rightleftharpoons } \underset{\mathrm{conjugate} \mathrm{acid}}{ {\mathrm{H}}_3{\mathrm{O}}_{\left(\mathrm{aq}\right)}^{+}}+\underset{\mathrm{Y}}{{\mathrm{OH}}_{\left(\mathrm{aq}\right)}^{-}}$

X and Y respectively are