The conjugate acid to the Brønsted-Lowry base $\ce{OH−}$ is $\ce{H2O}$, just added a proton to $\ce{OH−}$.

$$\ce{B(aq) + H+(aq) <=> BH+(aq)}$$

$$\ce{OH-(aq) + H+(aq) <=> H2O(l)}$$

where $\ce{B} = \ce{OH-}$

OTOH, $\ce{H2O}$ is also the conjugate base to $\ce{H3O+}$.

$\ce{Na+}$ in water, is an extremely weak Lewis acid, but it reacts in gaseous phase with Lewis base $\ce{Cl-}$, forming an ionic pair $\ce{Na+Cl-}$.

$\ce{Na+}$ could be formally considered as a conjugate Arrhenius acid to $\ce{NaOH}$, but I am not sure if the concept of conjugate pairs is ever used in the Arrhenius theory.

The conjugate acid to the Brønsted-Lowry base $\ce{OH−}$ is $\ce{H2O}$, just added a proton to $\ce{OH−}$.

$$\ce{B(aq) + H+(aq) <=> BH+(aq)}$$

$$\ce{OH-(aq) + H+(aq) <=> H2O(l)}$$

where $\ce{B} = \ce{OH-}$

OTOH, $\ce{H2O}$ is also the conjugate base to $\ce{H3O+}$.

$\ce{Na+(aq)}$ is an extremely weak Lewis acid. But in a gaseous phase, as a naked ion, it reacts with Lewis base $\ce{Cl-}$, forming an ionic pair $\ce{Na+Cl-}$.

$\ce{Na+}$ could be formally considered as a conjugate Arrhenius acid to $\ce{NaOH}$, but I am not sure if the concept of conjugate pairs is ever used in the Arrhenius theory.

The conjugate acid to the Broensted-Lawry base $\ce{OH−}$ is $\ce{H2O}$, just added a proton to $\ce{OH−}$.

$$\ce{B(aq) + H+(aq) <=> BH+(aq)}$$

$$\ce{OH(aq) + H+(aq) <=> H2O(l)}$$

where $\ce{B} = \ce{OH-}$

OTOH, $\ce{H2O}$ is also the conjugate base to $\ce{H3O+}$.

$\ce{Na+}$ is in water an extremely weak Lewis acid, but it reacts in gaseous phase with Lewis base $\ce{Cl-}$, forming a ionic pair $\ce{Na+Cl-}$.

$\ce{Na+}$ could be formally considered as a conjugate Arrhenius acid to $\ce{NaOH}$, but I am not sure if the concept of conjugate pairs is ever used in the Arrhenius theory.

The conjugate acid to the Brønsted-Lowry base $\ce{OH−}$ is $\ce{H2O}$, just added a proton to $\ce{OH−}$.

$$\ce{B(aq) + H+(aq) <=> BH+(aq)}$$

$$\ce{OH-(aq) + H+(aq) <=> H2O(l)}$$

where $\ce{B} = \ce{OH-}$

OTOH, $\ce{H2O}$ is also the conjugate base to $\ce{H3O+}$.

$\ce{Na+}$ in water, is an extremely weak Lewis acid, but it reacts in gaseous phase with Lewis base $\ce{Cl-}$, forming an ionic pair $\ce{Na+Cl-}$.

$\ce{Na+}$ could be formally considered as a conjugate Arrhenius acid to $\ce{NaOH}$, but I am not sure if the concept of conjugate pairs is ever used in the Arrhenius theory.