Textbook Problem

Write the formula and the give the name of the conjugate base of each of the following acids.

1. a) $\text{HCN}$
2. b) ${\text{HSO}}_{\text{4}}^{-}$
3. c) $\text{HF}$

Interpretation Introduction

Interpretation:

Formula and the conjugate base of given acid has to be written.

Concept Introduction:

Arrhenius Acids and Bases

Acid release hydrogen ion in water

Base release hydroxide ions in water.

$\begin{array}{l}\text{HCl(aq) }\to {\text{H}}^{\text{+}}{\text{(aq) + Cl}}^{\text{-}}\text{(aq)}\mathrm{.........}\text{Acid}\\ \text{NaOH(aq) }\to {\text{Na}}^{\text{+}}{\text{(aq)+ OH}}^{\text{-}}\text{(aq)}\mathrm{...........}\text{Base}\end{array}$

An acid is a substance that produces hydronium ions, ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$ when dissolved in water.

Bronsted –Lowry definitions:

A Bronsted –Lowry acid is a proton donor, it donates a hydrogen ion, ${\text{H}}^{\text{+}}$

A Bronsted-Lowry base is a proton acceptor, it accepts a hydrogen ion ${\text{H}}^{\text{+}}$.

Lewis definition:

A Lewis acid is a substance that can accept and share an electron pair.

A Lewis base is a substance that can donate and share an electron pair.

Bronsted –Lowry conjugate acid-Base pairs:

When an acid is dissolved in water, the acid $\text{(HA)}$ donates a proton to water to form a new acid (conjugate acid) and a new base (conjugate base).

Answer to Problem 1PS

The conjugate base of $\text{HCN}$ is Cyanide ion (${\text{CN}}^{\text{-}}$)

Explanation of Solution

$\text{HCN}$ is an acid .Cyanide ion (${\text{CN}}^{\text{-}}$) is a conjugate base. $\text{HCN}$ and (${\text{CN}}^{\text{-}}$) is differs by only one proton. Therefore, (${\text{CN}}^{\text{-}}$) is a conjugate base of $\text{HCN}$

Interpretation Introduction

Interpretation:

Formula and the conjugate base of given acid has to be written.

Concept Introduction:

Arrhenius Acids and Bases

Acid release hydrogen ion in water

Base release hydroxide ions in water.

$\begin{array}{l}\text{HCl(aq) }\to {\text{H}}^{\text{+}}{\text{(aq) + Cl}}^{\text{-}}\text{(aq)}\mathrm{.........}\text{Acid}\\ \text{NaOH(aq) }\to {\text{Na}}^{\text{+}}{\text{(aq)+ OH}}^{\text{-}}\text{(aq)}\mathrm{...........}\text{Base}\end{array}$

An acid is a substance that produces hydronium ions, ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$ when dissolved in water.

Bronsted –Lowry definitions:

A Bronsted –Lowry acid is a proton donor, it donates a hydrogen ion, ${\text{H}}^{\text{+}}$

A Bronsted-Lowry base is a proton acceptor, it accepts a hydrogen ion ${\text{H}}^{\text{+}}$.

Lewis definition:

A Lewis acid is a substance that can accept and share an electron pair.

A Lewis base is a substance that can donate and share an electron pair.

Bronsted –Lowry conjugate acid-Base pairs:

When an acid is dissolved in water, the acid $\text{(HA)}$ donates a proton to water to form a new acid (conjugate acid) and a new base (conjugate base).

Answer to Problem 1PS

The conjugate base of ${\text{HSO}}_{\text{4}}^{\text{-}}$ is sulphate ion ${\text{SO}}_{\text{4}}^{\text{2-}}$.

Explanation of Solution

${\text{HSO}}_{\text{4}}^{\text{-}}$ is an acid .sulphate ion (${\text{SO}}_{\text{4}}^{\text{2-}}$) is a conjugate base. ${\text{HSO}}_{\text{4}}^{\text{-}}$ and (${\text{SO}}_{\text{4}}^{\text{2-}}$) is differs by only one proton. Therefore,( ${\text{SO}}_{\text{4}}^{\text{2-}}$) ion is a conjugate base of ${\text{HSO}}_{\text{4}}^{\text{-}}$

Interpretation Introduction

Interpretation:

Formula and the conjugate base of given acid has to be written.

Concept Introduction:

Arrhenius Acids and Bases

Acid release hydrogen ion in water

Base release hydroxide ions in water.

$\begin{array}{l}\text{HCl(aq) }\to {\text{H}}^{\text{+}}{\text{(aq) + Cl}}^{\text{-}}\text{(aq)}\mathrm{.........}\text{Acid}\\ \text{NaOH(aq) }\to {\text{Na}}^{\text{+}}{\text{(aq)+ OH}}^{\text{-}}\text{(aq)}\mathrm{...........}\text{Base}\end{array}$

An acid is a substance that produces hydronium ions, ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$ when dissolved in water.

Bronsted –Lowry definitions:

A Bronsted –Lowry acid is a proton donor, it donates a hydrogen ion, ${\text{H}}^{\text{+}}$

A Bronsted-Lowry base is a proton acceptor, it accepts a hydrogen ion ${\text{H}}^{\text{+}}$.

Lewis definition:

A Lewis acid is a substance that can accept and share an electron pair.

A Lewis base is a substance that can donate and share an electron pair.

Bronsted –Lowry conjugate acid-Base pairs:

When an acid is dissolved in water, the acid $\text{(HA)}$ donates a proton to water to form a new acid (conjugate acid) and a new base (conjugate base).

Answer to Problem 1PS

The conjugate base of $\text{HF}$ is fluoride ion (${\text{F}}^{-}$).

Explanation of Solution

$\text{HF}$ is an acid .Fluoride ion (${\text{F}}^{\text{-}}$) is a conjugate base. $\text{HF}$ and (${\text{F}}^{\text{-}}$) is differs by only one proton. Therefore, Fluoride (${\text{F}}^{\text{-}}$) is a conjugate base of $\text{HF}$