Write the conjugate acid and conjugate base of each of the following:
(a) OH^- (b) H2O (c) HCO3^- (d) H2O2

Question

Write the conjugate acid and conjugate base of each of the following:
(a) OH^-   (b) H2O   (c) HCO3^-   (d) H2O2

Accepted Answer

>

> [!TLDR]
> Add a proton (H+) to get the conjugate acid, remove a proton to get the conjugate base. Results: OH^- -> H2O / O^2-;  H2O -> H3O^+ / OH^-;  HCO3^- -> H2CO3 / CO3^2-;  H2O2 -> H3O2^+ / HO2^-.
>
> **Bronsted-Lowry rule:** An acid is a proton (H+) donor and a base is a proton acceptor. For any species:
> - its **conjugate acid** is obtained by ADDING one H+ (and raising the charge by +1);
> - its **conjugate base** is obtained by REMOVING one H+ (and lowering the charge by -1).
>
> **(a) OH^-**
> - Conjugate acid (add H+): OH^- + H+ = **H2O**
> - Conjugate base (remove H+): OH^- - H+ = **O^2-**
>
> **(b) H2O**
> - Conjugate acid (add H+): H2O + H+ = **H3O^+**
> - Conjugate base (remove H+): H2O - H+ = **OH^-**
>
> **(c) HCO3^-** …

Acid	Conjugate Base	Base	Conjugate Acid
$\text{HCl}$	$\text{Cl}^-$	$\text{NH}_3$	$\text{NH}_4^+$
$\text{H}_2\text{SO}_4$	$\text{HSO}_4^-$	$\text{H}_2\text{O}$	$\text{H}_3\text{O}^+$
$\text{NH}_4^+$	$\text{NH}_3$	$\text{OH}^-$	$\text{H}_2\text{O}$
$\text{H}_2\text{O}$	$\text{OH}^-$	$\text{CO}_3^{2-}$	$\text{HCO}_3^-$

Q.Write the conjugate acid and conjugate base of each of the following:

Concept understanding — Brønsted Lowry Conjugate Pairs

From Intuition to Precision: Brønsted–Lowry Conjugate Pairs

The Precise Statement

Seeing It in Action

A Quick Reference Table

Why This Matters …

Q.Write the conjugate acid and conjugate base of each of the following:

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