Chapter 13, Problem 113A

Interpretation Introduction

(a)

Interpretation:

The given equation is to be balanced:

Zinc displaces silver in silver chloride

Concept introduction:

It is a redox reaction. The reaction is balanced when electrons produced at anode are taken by cathode.

Answer to Problem 113A

$\text{Zn+2AgCl}\to {\text{ZnCl}}_{\text{2}}\text{+2Ag}$

Explanation of Solution

The reaction can be explained as:

Zinc converts into ${\text{Zn}}^{\text{+2}}$ by loss of 2 electrons and ${\text{Ag}}^{\text{+}}$ gains one electron to convert to $\text{Ag}$. Therefore 2 moles of silver chloride combines with zinc to form zinc chloride and silver.

(b)

Interpretation Introduction

Interpretation:

The given equation is to be balanced:

Sodium hydroxide and sulphuric acid react to form sodium sulphate and water

Concept introduction:

A balanced chemical equation is one which contains same number of atoms of the element at both sides of the reaction.

Answer to Problem 113A

${\text{2NaOH+H}}_{\text{2}}{\text{SO}}_{\text{4}}\to {\text{Na}}_{\text{2}}{\text{SO}}_{\text{4}}{\text{+2H}}_{\text{2}}\text{O}$

Explanation of Solution

Two moles of sodium hydroxide combines with one mole of sulphuric acid to form one mole of sodium sulphate and two moles of water.