Chapter 10, Problem 10.60P

(a)

Interpretation Introduction

Interpretation:

The reaction of potassium chromate and lead nitrate has to be classified as precipitation, acid-base or gas –forming reaction.

Concept Introduction:

Double replacement reactions:  This type of reactions occurs when the cations and the anions switch between two reactants to form new products.  In order for the reaction to occur, one of the products is usually a solid precipitate, a gas or a molecular compound.

Acid-Base reactions:  A chemical reaction between an acid and a base is called as neutralization reaction.  The ionic compound is formed along with water in this reaction is called as salt.

Answer to Problem 10.60P

The reaction of potassium chromate and lead nitrate is precipitation reaction.

Explanation of Solution

The product of the reaction between aqueous lead (II) nitrate and aqueous potassium chromate is lead chromate and potassium nitrate.  The completed equation is,

  $\begin{array}{l}{\text{K}}_{\text{2}}{\text{CrO}}_{\text{4(aq)}}\text{+Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2(aq)}}\stackrel{}{\to }{\text{PbCrO}}_{\text{4(s)}}{\text{+KNO}}_{\text{3(aq)}}\\ \text{Potassium}\text{Lead(II)}\text{Lead}\text{Potassium}\\ \text{chromate}\text{nitrate}\text{chromate}\text{nitrate}\end{array}$

The balanced equation is,

  ${\text{K}}_{\text{2}}{\text{CrO}}_{\text{4(aq)}}\text{+Pb}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2(aq)}}\stackrel{}{\to }{\text{PbCrO}}_{\text{4(s)}}{\text{+2KNO}}_{\text{3(aq)}}$

The reaction of potassium chromate and lead nitrate is precipitation reaction.  An insoluble salt, lead chromate is formed as precipitate.

(b)

Interpretation Introduction

Interpretation:

The reaction of hydrochloric acid and sodium sulphide has to be classified as precipitation, acid-base or gas –forming reaction.

Concept Introduction:

Refer to part (a).

Answer to Problem 10.60P

The reaction of hydrochloric acid and sodium sulphide is gas-forming reaction.

Explanation of Solution

The product of the reaction between hydrochloric acid and aqueous sodium sulphide is sodium chloride and hydrogen sulphide.  The completed equation is,

  $\begin{array}{l}{\text{HCl}}_{\left(\text{aq}\right)}{\text{+Na}}_{\text{2}}{\text{S}}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{NaCl}}_{\left(\text{aq}\right)}{\text{+H}}_{\text{2}}{\text{S}}_{\left(\text{g}\right)}\\ \text{Hydrochloric}\text{Sodium}\text{Sodium}\text{Hydrogen}\\ \text{acid}\text{sulphide}\text{chloride}\text{sulphide}\end{array}$

The balanced equation is,

  ${\text{2HCl}}_{\left(\text{aq}\right)}{\text{+Na}}_{\text{2}}{\text{S}}_{\left(\text{aq}\right)}\stackrel{}{\to }2{\text{NaCl}}_{\left(\text{aq}\right)}{\text{+H}}_{\text{2}}{\text{S}}_{\left(\text{g}\right)}$

In the reaction between hydrochloric acid and sodium sulphide, gaseous hydrogen sulphide is formed as one of the products.  Hence, the reaction of hydrochloric acid and sodium sulphide is gas-forming reaction.

(c)

Interpretation Introduction

The reaction of barium hydroxide and zinc sulphate has to be classified as precipitation, acid-base or gas –forming reaction.

Concept Introduction:

Refer to part (a).

Answer to Problem 10.60P

The reaction of barium hydroxide and zinc sulphate is precipitation reaction.

Explanation of Solution

The product of the reaction between aqueous barium hydroxide and aqueous zinc sulphate is barium sulphate and zinc hydroxide.  The completed equation is,

  $\begin{array}{l}\text{Ba}{\left(\text{OH}\right)}_{\text{2(aq)}}{\text{+ZnSO}}_{\text{4(aq)}}\stackrel{}{\to }{\text{BaSO}}_{\text{4(s)}}\text{+Zn}{\left(\text{OH}\right)}_{\text{2(aq)}}\\ \text{Barium}\text{Zinc}\text{Barium}\text{Zinc}\\ \text{hydroxide}\text{sulphate}\text{sulphate}\text{hydroxide}\end{array}$

The double displacement reaction of aqueous barium hydroxide and aqueous zinc sulphate is self-balanced.

The reaction of barium hydroxide and zinc sulphate is precipitation reaction.  An insoluble salt, barium sulphate is formed as precipitate.

(d)

Interpretation Introduction

The reaction of calcium oxide and nitric acid has to be classified as precipitation, acid-base or gas –forming reaction.

Concept Introduction:

Refer to part (a).

Answer to Problem 10.60P

The reaction of calcium oxide and nitric acid is acid-base reaction.

Explanation of Solution

The product of the reaction between aqueous nitric acid and solid calcium oxide is calcium nitrate and water.  The completed equation is,

  $\begin{array}{l}{\text{HNO}}_{\text{3(aq)}}{\text{+CaO}}_{\left(\text{s}\right)}\stackrel{}{\to }\text{Ca}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2(aq)}}{\text{+H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}\\ \text{Nitric}\text{Calcium}\text{Calcium}\text{Water}\\ \text{acid}\text{oxide}\text{nitrate}\end{array}$

The balanced equation is,

  ${\text{2HNO}}_{\text{3(aq)}}{\text{+CaO}}_{\left(\text{s}\right)}\stackrel{}{\to }\text{Ca}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2(aq)}}{\text{+H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}$

The reaction of calcium oxide and nitric acid is acid-base reaction.  Hydrochloric acid neutralizes calcium oxide and calcium nitrate is formed as a product.