Chapter 16, Problem 16.98QP

(a)

Interpretation Introduction

Interpretation:

The pH of aqueous solutions containing the given salts has to be predicted

Concept Information:

Salt hydrolysis is a reaction in which the ion of salt reacts with water and produce either hydronium ion or hydroxide ion.

• In other words, when an ionic compound bearing a weak base as its anion, dissolves in water undergoes hydrolysis.  The weak base anion accepts a proton from water and produce its conjugate base and hydroxide ion.
• For Example: The dissociation of salt $\text{NaF}$ gives ${\text{Na}}^{\text{+}}$ and ${\text{F}}^{\text{-}}$ ions. The ions of $\text{NaF}$ reacts with water and produce hydroxide ions, which impacts the pH of the solution.

${\text{F}}^{-}{}_{(aq)}+{\text{H}}_{\text{2}}{\text{O}}_{(l)}\rightleftarrows {\text{HF}}_{(aq)}+{\text{OH}}^{\text{-}}{}_{(aq)}$

• In general, cations that are strong conjugate acids, anions that are strong conjugate bases, and small, highly charged metal ions will undergo hydrolysis.
• The extent of hydrolysis is depends on the charge and size of the metal cation.  The metal cation with small size and high charge shows greatest extent of hydrolysis because compact, highly charged ion is more effective in polarizing the  $\text{OH}$  bond and facilitates ionization.
• If the anion of salt forms weak acid, then hydrolysis takes place

pH scale:

The acidity or basicity of an aqueous solution was said using a numerical scale called pH scale.

Based on pH of the solution, salt solutions can be classified as

• Acidic-(pH will be less than seven)
• Basic -(pH will be more than seven)
• Neutral -(pH will be equal to seven)

To Predict: The pH of aqueous solutions containing the given $\text{KBr}$

(b)

Interpretation Introduction

Interpretation:

The pH of aqueous solutions containing the given salts has to be predicted

Concept Information:

Salt hydrolysis is a reaction in which the ion of salt reacts with water and produce either hydronium ion or hydroxide ion.

• In other words, when an ionic compound bearing a weak base as its anion, dissolves in water undergoes hydrolysis.  The weak base anion accepts a proton from water and produce its conjugate base and hydroxide ion.
• For Example: The dissociation of salt $\text{NaF}$ gives ${\text{Na}}^{\text{+}}$ and ${\text{F}}^{\text{-}}$ ions. The ions of $\text{NaF}$ reacts with water and produce hydroxide ions, which impacts the pH of the solution.

${\text{F}}^{-}{}_{(aq)}+{\text{H}}_{\text{2}}{\text{O}}_{(l)}\rightleftarrows {\text{HF}}_{(aq)}+{\text{OH}}^{\text{-}}{}_{(aq)}$

• In general, cations that are strong conjugate acids, anions that are strong conjugate bases, and small, highly charged metal ions will undergo hydrolysis.
• The extent of hydrolysis is depends on the charge and size of the metal cation.  The metal cation with small size and high charge shows greatest extent of hydrolysis because compact, highly charged ion is more effective in polarizing the  $\text{OH}$  bond and facilitates ionization.
• If the anion of salt forms weak acid, then hydrolysis takes place

pH scale:

The acidity or basicity of an aqueous solution was said using a numerical scale called pH scale.

Based on pH of the solution, salt solutions can be classified as

• Acidic-(pH will be less than seven)
• Basic -(pH will be more than seven)
• Neutral -(pH will be equal to seven)

To Predict: The pH of aqueous solutions containing the given ${\text{Al(NO}}_{\text{3}}{\text{)}}_{\text{3}}$

(c)

Interpretation Introduction

Interpretation:

The pH of aqueous solutions containing the given salts has to be predicted

Concept Information:

Salt hydrolysis is a reaction in which the ion of salt reacts with water and produce either hydronium ion or hydroxide ion.

• In other words, when an ionic compound bearing a weak base as its anion, dissolves in water undergoes hydrolysis.  The weak base anion accepts a proton from water and produce its conjugate base and hydroxide ion.
• For Example: The dissociation of salt $\text{NaF}$ gives ${\text{Na}}^{\text{+}}$ and ${\text{F}}^{\text{-}}$ ions. The ions of $\text{NaF}$ reacts with water and produce hydroxide ions, which impacts the pH of the solution.

${\text{F}}^{-}{}_{(aq)}+{\text{H}}_{\text{2}}{\text{O}}_{(l)}\rightleftarrows {\text{HF}}_{(aq)}+{\text{OH}}^{\text{-}}{}_{(aq)}$

• In general, cations that are strong conjugate acids, anions that are strong conjugate bases, and small, highly charged metal ions will undergo hydrolysis.
• The extent of hydrolysis is depends on the charge and size of the metal cation.  The metal cation with small size and high charge shows greatest extent of hydrolysis because compact, highly charged ion is more effective in polarizing the  $\text{OH}$  bond and facilitates ionization.
• If the anion of salt forms weak acid, then hydrolysis takes place

pH scale:

The acidity or basicity of an aqueous solution was said using a numerical scale called pH scale.

Based on pH of the solution, salt solutions can be classified as

• Acidic-(pH will be less than seven)
• Basic -(pH will be more than seven)
• Neutral -(pH will be equal to seven)

To Predict: The pH of aqueous solutions containing the given ${\text{BaCl}}_{\text{2}}$

(d)

Interpretation Introduction

Interpretation:

The pH of aqueous solutions containing the given salts has to be predicted

Concept Information:

Salt hydrolysis is a reaction in which the ion of salt reacts with water and produce either hydronium ion or hydroxide ion.

• In other words, when an ionic compound bearing a weak base as its anion, dissolves in water undergoes hydrolysis.  The weak base anion accepts a proton from water and produce its conjugate base and hydroxide ion.
• For Example: The dissociation of salt $\text{NaF}$ gives ${\text{Na}}^{\text{+}}$ and ${\text{F}}^{\text{-}}$ ions. The ions of $\text{NaF}$ reacts with water and produce hydroxide ions, which impacts the pH of the solution.

${\text{F}}^{-}{}_{(aq)}+{\text{H}}_{\text{2}}{\text{O}}_{(l)}\rightleftarrows {\text{HF}}_{(aq)}+{\text{OH}}^{\text{-}}{}_{(aq)}$

• In general, cations that are strong conjugate acids, anions that are strong conjugate bases, and small, highly charged metal ions will undergo hydrolysis.
• The extent of hydrolysis is depends on the charge and size of the metal cation.  The metal cation with small size and high charge shows greatest extent of hydrolysis because compact, highly charged ion is more effective in polarizing the  $\text{OH}$  bond and facilitates ionization.
• If the anion of salt forms weak acid, then hydrolysis takes place

pH scale:

The acidity or basicity of an aqueous solution was said using a numerical scale called pH scale.

Based on pH of the solution, salt solutions can be classified as

• Acidic-(pH will be less than seven)
• Basic -(pH will be more than seven)
• Neutral -(pH will be equal to seven)

To Predict:  The pH of aqueous solutions containing the given ${\text{Bi(NO}}_{\text{3}}{\text{)}}_{\text{3}}$