Chapter U4.18, Problem 4E

(a)

Interpretation Introduction

Interpretation: Thehydroiodic acid HI needs to be classified as an acid or a base. Also, the ions formed in its solution needs to be represented.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 4E

  ${\text{HI}}_{\text{(aq) }}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+I}}^{\text{-}}{}_{\text{(aq)}}$

Hydroiodic acid = HI = Acid

Explanation of Solution

Acidic and basic substance can also be classified on the basis of taste. Acidic substances are sour in taste whereas basic substances are bitter in taste.

In hydroiodic acid HI, there is one H atom and it can give ${\text{H}}^{\text{+}}$ ions in its solution therefore it must be an acid. The acid dissociation for hydroiodic acid can be shown as:

  ${\text{HI}}_{\text{(aq) }}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+I}}^{\text{-}}{}_{\text{(aq)}}$

(b)

Interpretation Introduction

Interpretation: Theformic acid HCOOH needs to be classified as an acid or a base. Also, the ions formed in its solution needs to be represented.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 4E

  ${\text{HCOOH}}_{\text{(aq) }}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+ HCOO}}^{\text{-}}{}_{\text{(aq)}}$

Formic acid = HCOOH = Acid

Explanation of Solution

Acidic and basic substance can also be classified on the basis of taste. Acidic substances are sour in taste whereas basic substances are bitter in taste.

In formic acid HCOOH, there is one ionizable H atom and it can give ${\text{H}}^{\text{+}}$ ions in its solution therefore it must be an acid. The acid dissociation for formic acid can be shown as:

  ${\text{HCOOH}}_{\text{(aq) }}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+ HCOO}}^{\text{-}}{}_{\text{(aq)}}$

(c)

Interpretation Introduction

Interpretation: Therubidium hydroxide RbOH needs to be classified as an acid or a base. Also, the ions formed in its solution needs to be represented.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 4E

  ${\text{RbOH}}_{\text{(aq) }}\stackrel{{\text{H}}_{\text{2}}{\text{O}}_{\text{(l)}}}{\to }{\text{Rb}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+ OH}}^{\text{-}}{}_{\text{(aq)}}$

Rubidium hydroxide RbOH= base

Explanation of Solution

Acidic and basic substance can also be classified on the basis of taste. Acidic substances are sour in taste whereas basic substances are bitter in taste.

In Rubidium hydroxide RbOH, there is one OH group and it can give ${\text{OH}}^{\text{-}}$ ions in its solution therefore it must be a base. The base dissociation forRbOHcan be shown as:

  ${\text{RbOH}}_{\text{(aq) }}\stackrel{{\text{H}}_{\text{2}}{\text{O}}_{\text{(l)}}}{\to }{\text{Rb}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+ OH}}^{\text{-}}{}_{\text{(aq)}}$

(d)

Interpretation Introduction

Interpretation: Thehypochlorus acid HOCl needs to be classified as an acid or a base. Also, the ions formed in its solution needs to be represented.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 4E

  ${\text{HOCl}}_{\text{(aq) }}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+ ClO}}^{\text{-}}{}_{\text{(aq)}}$

Hypochlorus acid HOCl= Acid

Explanation of Solution

Acidic and basic substance can also be classified on the basis of taste. Acidic substances are sour in taste whereas basic substances are bitter in taste.

In Hypochlorus acid HOCl, there is one H atom and it can give ${\text{H}}^{\text{+}}$ ions in its solution therefore it must be an acid. The acid dissociation for hypochlorus acid HOClcan be shown as:

  ${\text{HOCl}}_{\text{(aq) }}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+ ClO}}^{\text{-}}{}_{\text{(aq)}}$

(e)

Interpretation Introduction

Interpretation: Theselenous acid ${\text{H}}_{\text{2}}{\text{SeO}}_{\text{4}}$ needs to be classified as an acid or a base. Also, the ions formed in its solution needs to be represented.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 4E

  ${\text{H}}_{\text{2}}{\text{SeO}}_{\text{4}}{}_{\text{(aq) }}{\text{ + 2 H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{2 H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+ SeO}}_{\text{4}}{{}^{\text{2-}}}_{\text{(aq)}}$

Selenous acid ${\text{H}}_{\text{2}}{\text{SeO}}_{\text{4}}$ = Acid

Explanation of Solution

Acidic and basic substance can also be classified on the basis of taste. Acidic substances are sour in taste whereas basic substances are bitter in taste.

In Selenousacid ${\text{H}}_{\text{2}}{\text{SeO}}_{\text{4}}$ , there are two ionizable H atoms and it can give ${\text{H}}^{\text{+}}$ ions in its solution therefore it must be an acid. The acid dissociation for selenous acid ${\text{H}}_{\text{2}}{\text{SeO}}_{\text{4}}$ can be shown as:

  ${\text{H}}_{\text{2}}{\text{SeO}}_{\text{4}}{}_{\text{(aq) }}{\text{ + 2 H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{2 H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+ SeO}}_{\text{4}}{{}^{\text{2-}}}_{\text{(aq)}}$

(f)

Interpretation Introduction

Interpretation: Thephosphine ${\text{PH}}_{\text{3}}$ needs to be classified as an acid or a base. Also, the ions formed in its solution needs to be represented.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 4E

  ${\text{PH}}_{\text{3}}{}_{\text{(aq) }}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{ PH}}_4{{}^{\text{+}}}_{{}_{\text{(aq)}}}{\text{+ OH}}^{\text{-}}{}_{\text{(aq)}}$

  ${\text{PH}}_{\text{3}}$ = base

Explanation of Solution

Acidic and basic substance can also be classified on the basis of taste. Acidic substances are sour in taste whereas basic substances are bitter in taste.

Phosphine ${\text{PH}}_{\text{3}}$ gives OH- ions in its aqueous solution by accepting hydrogen from water so it must be basic in nature.

  ${\text{PH}}_{\text{3}}{}_{\text{(aq) }}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{ PH}}_4{{}^{\text{+}}}_{{}_{\text{(aq)}}}{\text{+ OH}}^{\text{-}}{}_{\text{(aq)}}$

(g)

Interpretation Introduction

Interpretation: Theperchloric acid ${\text{HClO}}_{\text{4}}$ needs to be classified as an acid or a base. Also, the ions formed in its solution needs to be represented.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 4E

  ${\text{HClO}}_{\text{4}}{}_{\text{(aq) }}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{ H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+ ClO}}_{\text{4}}{{}^{\text{-}}}_{\text{(aq)}}$

Perchloric acid ${\text{HClO}}_{\text{4}}$ = Acid

Explanation of Solution

Acidic and basic substance can also be classified on the basis of taste. Acidic substances are sour in taste whereas basic substances are bitter in taste.

Perchloric acid ${\text{HClO}}_{\text{4}}$ there is one H atom and it can give ${\text{H}}^{\text{+}}$ ions in its solution therefore it must be an acid. The acid dissociation for perchloric acid can be shown as:

  ${\text{HClO}}_{\text{4}}{}_{\text{(aq) }}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{ H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{{}_{\text{(aq)}}}{\text{+ ClO}}_{\text{4}}{{}^{\text{-}}}_{\text{(aq)}}$

(h)

Interpretation Introduction

Interpretation: Thecalcium hydroxide ${\text{Ca(OH)}}_{\text{2}}$ needs to be classified as an acid or a base. Also, the ions formed in its solution needs to be represented.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 4E

  ${\text{Ca(OH)}}_{\text{2}}{}_{\text{(aq) }}\stackrel{{\text{H}}_{\text{2}}{\text{O}}_{\text{(l)}}}{\to }{\text{Ca}}^{\text{2+}}{}_{{}_{\text{(aq)}}}{\text{+ 2 OH}}^{\text{-}}{}_{\text{(aq)}}$

Calcium hydroxide ${\text{Ca(OH)}}_{\text{2}}$ = Base

Explanation of Solution

Acidic and basic substance can also be classified on the basis of taste. Acidic substances are sour in taste whereas basic substances are bitter in taste.

In calcium hydroxide ${\text{Ca(OH)}}_{\text{2}}$ , there are two OH groups and it can give ${\text{OH}}^{\text{-}}$ ions in its solution therefore it must be a base. The base dissociation for ${\text{OH}}^{\text{-}}$ can be shown as:

  ${\text{Ca(OH)}}_{\text{2}}{}_{\text{(aq) }}\stackrel{{\text{H}}_{\text{2}}{\text{O}}_{\text{(l)}}}{\to }{\text{Ca}}^{\text{2+}}{}_{{}_{\text{(aq)}}}{\text{+ 2 OH}}^{\text{-}}{}_{\text{(aq)}}$