Question

Identifying the Conjugate Base Which is the conjugate base in each of the pairs below?

Answer 1

Answer:

$RCOO^{-}\\RNH_{2}\\H_{2}PO_{4}^{-}\\HCO_{3-}$

Explanation:

A conjugate base is formed when an acid in reaction with a base lose a proton H+.

For example if RCOOH that is an acid, reacts with water that is a base, the RCOOH loses an H+ and it becomes $RCOO^{-}$ that is the conjugate base; and the water gains the H+ and become the conjugate acid, that is:

* $RCOOH, RCOO-$

$RCOOH+H_{2}O=H_{3}O^{+}+RCOO^{-}$

The RCOO- is the conjugate base

* $RNH_{2}, RNH_{3}^{+}$

$RNH_{3}^{+}+H_{2}O=H_{3}O^{+}+RNH_{2}$

In this case the $RNH_{2}$ is the conjugate base

* $H_{3}PO_{4},H_{2}PO_{4}^{-}$

$H_{3}PO_{4}+H_{2}O=H_{3}O^{+}+H_{2}PO_{4}^{-}$

The $H_{2}PO_{4}^{-}$ is the conjugate base

* $H_{2}CO_{3},HCO_{3}^{-}$

$H_{2}CO_{3}+H_{2}O=H_{3}O^{+}+HCO_{3}^{-}$

The $HCO_{3}^{-}$ is the conjugate base.