Chapter 8, Problem 31A

Interpretation Introduction

Interpretation:

The double − displacement reaction and single replacement reaction needs to be explained with examples.

Concept Introduction:

A chemical reaction in which the reactant ions change their places and form new products is known as double displacement reaction.

A chemical reaction in which one reactant is changed with one ion of a second reactant is known as single − replacement reaction.

Explanation of Solution

A chemical reaction in which the reactant ions change their places and form new products is known as double displacement reaction. In double displacement reaction the chemical bond between the reactants may be ionic or covalent. It is also known as double replacement reaction or double decomposition reaction.

The double displacement reaction can be written as:

  $\text{AB}\text{+}\text{CD}\to \text{AD}\text{+}\text{CB}$

The examples of double displacement reaction are shown below:

  ${\text{AgNO}}_{\text{3}}\text{+}\text{NaCl}\to \text{AgCl}\text{+}{\text{NaNO}}_{\text{3}}$

The reaction between silver nitrate and sodium chloride is a type of double displacement reaction which forms silver chloride and sodium nitrate

  ${\text{BaCl}}_{\text{2}}\text{+}{\text{Na}}_{\text{2}}{\text{SO}}_{\text{4}}\to {\text{BaSO}}_{\text{4}}\text{+}\text{2NaCl}$

The reaction between barium chloride and sodium sulphate is also a type of double displacement reaction which forms precipitate of barium sulphate and sodium chloride as a product.

A chemical reaction in which one reactant is changed with one ion of a second reactant is known as single − replacement reaction.

The single replacement reaction can be written as:

  $\text{A}\text{+}\text{BC}\to \text{B+}\text{AC}$

The examples of single replacement reaction are shown below:

  $\text{Zn}\text{+}\text{2HCl}\to {\text{ZnCl}}_{\text{2}}\text{+}{\text{H}}_{\text{2}}$

The reaction between Zn metal and hydrochloric acid is a type of single replacement reaction which form zinc chloride and hydrogen gas

  ${\text{2Fe}}_{\text{2}}{\text{O}}_{\text{3}}\text{+}\text{3C}\to \text{Fe}\text{+}{\text{CO}}_{\text{2}}$

In the single replacement reaction iron oxide solution used coke as a carbon source.