Chapter 18, Problem 50A

(a)

Interpretation Introduction

Interpretation: The element which is getting oxidised and which is getting reduced needs to be identified by assigning oxidation states.

  ${\text{2 B}}_{\text{2}}{\text{O}}_{\text{3}}{}_{\text{(s)}}{\text{ + 6 Cl}}_{\text{2(g)}}\stackrel{}{\to }{\text{ 4 BCl}}_{\text{3(l)}}{\text{+ 3 O}}_{\text{2}}{}_{\text{(g)}}$

Concept Introduction: A Redox reaction leads to oxidation and reduction processes simultaneously. Oxidation and reduction reactions are the processes involved in the loss or gain of electron. Oxidation is the process that is involved in the loss of electrons and oxidized to cation whereas reduction is the process that is involved in the gain of electrons and reduced to anion.

Answer to Problem 50A

Element Cl reduced and O oxidizes.

Explanation of Solution

Assign oxidation number to each atom:

  $\begin{array}{l}{\text{2 B}}_{\text{2}}{\text{O}}_{\text{3}}{}_{\text{(s)}}{\text{ + 6 Cl}}_{\text{2(g)}}\stackrel{}{\to }{\text{ 4 BCl}}_{\text{3(l)}}{\text{+ 3 O}}_{\text{2}}{}_{\text{(g)}}\\ \text{ +3 -2 0 +3 -1 0}\end{array}$

Oxidation half-reaction must include oxidation step in which elements show increase in oxidation state.

Here the oxidation state of Cl decreases from 0 to -1. Thus, the Cl must be reduced.

Oxidation half-reaction must include oxidation step in which elements show increase in oxidation state. Here the oxidation state of O increases from-2 to 0. Thus, the oxygen is oxidized in the given reaction.

(b)

Interpretation Introduction

Interpretation: The element which is getting oxidised and which is getting reduced needs to be identified by assigning oxidation states.

  ${\text{GeH}}_{\text{4}}{}_{\text{(g)}}{\text{ + O}}_{\text{2(g)}}\stackrel{}{\to }{\text{Ge}}_{\text{(s)}}{\text{+ 2 H}}_{\text{2}}{\text{O}}_{\text{(g)}}$

Concept Introduction: A Redox reaction leads to oxidation and reduction processes simultaneously. Oxidation and reduction reactions are the processes involved in the loss or gain of electron. Oxidation is the process that is involved in the loss of electrons and oxidized to cation whereas reduction is the process that is involved in the gain of electrons and reduced to anion.

Answer to Problem 50A

Element O reduced and Ge oxidizes.

Explanation of Solution

Assign oxidation number to each atom:

  $\begin{array}{l}{\text{GeH}}_{\text{4}}{}_{\text{(g)}}{\text{ + O}}_{\text{2(g)}}\stackrel{}{\to }{\text{Ge}}_{\text{(s)}}{\text{+ 2 H}}_{\text{2}}{\text{O}}_{\text{(g)}}\\ \text{-4 +1 0 0 +1-2}\end{array}$

Oxidation half-reaction must include oxidation step in which elements show increase in oxidation state.

Here the oxidation state of O decreases from 0 to -2. Thus, the O must be reduced.

Oxidation half-reaction must include oxidation step in which elements show increase in oxidation state. Here the oxidation state of Ge increases from-4 to 0. Thus, the Ge is oxidized in the given reaction.

(c)

Interpretation Introduction

Interpretation: The element which is getting oxidised and which is getting reduced needs to be identified by assigning oxidation states.

  ${\text{C}}_{\text{2}}{\text{H}}_{\text{4}}{}_{\text{(g)}}{\text{ + Cl}}_{\text{2(g)}}\stackrel{}{\to }{\text{C}}_{\text{2}}{\text{H}}_{\text{4}}{\text{Cl}}_{\text{2(l)}}$

Concept Introduction: A Redox reaction leads to oxidation and reduction processes simultaneously. Oxidation and reduction reactions are the processes involved in the loss or gain of electron. Oxidation is the process that is involved in the loss of electrons and oxidized to cation whereas reduction is the process that is involved in the gain of electrons and reduced to anion.

Answer to Problem 50A

Element Cl reduced and C oxidizes.

Explanation of Solution

Assign oxidation number to each atom:

  $\begin{array}{l}{\text{C}}_{\text{2}}{\text{H}}_{\text{4}}{}_{\text{(g)}}{\text{ + Cl}}_{\text{2(g)}}\stackrel{}{\to }{\text{C}}_{\text{2}}{\text{H}}_{\text{4}}{\text{Cl}}_{\text{2(l)}}\\ \text{-2 +1 0 -1+1-1}\end{array}$

Oxidation half-reaction must include oxidation step in which elements show increase in oxidation state.

Here the oxidation state of Cl decreases from 0 to -1. Thus, the Cl must be reduced.

Oxidation half-reaction must include oxidation step in which elements show increase in oxidation state. Here the oxidation state of C increases from-2 to -1. Thus, the C is oxidized in the given reaction.

(d)

Interpretation Introduction

Interpretation: The element which is getting oxidised and which is getting reduced needs to be identified by assigning oxidation states.

  ${\text{O}}_2{}_{\text{(g)}}{\text{ + 2 F}}_{\text{2(g)}}\stackrel{}{\to }{\text{ 2 OF}}_{\text{2(g)}}$

Concept Introduction: A Redox reaction leads to oxidation and reduction processes simultaneously. Oxidation and reduction reactions are the processes involved in the loss or gain of electron. Oxidation is the process that is involved in the loss of electrons and oxidized to cation whereas reduction is the process that is involved in the gain of electrons and reduced to anion.

Answer to Problem 50A

Element F reduced and O oxidizes.

Explanation of Solution

Assign oxidation number to each atom:

  $\begin{array}{l}{\text{O}}_2{}_{\text{(g)}}{\text{ + 2 F}}_{\text{2(g)}}\stackrel{}{\to }{\text{ 2 OF}}_{\text{2(g)}}\\ \text{0 0 +2-1}\end{array}$

Oxidation half-reaction must include oxidation step in which elements show increase in oxidation state.

Here the oxidation state of F decreases from 0 to -1. Thus, the F must be reduced.

Oxidation half-reaction must include oxidation step in which elements show increase in oxidation state. Here the oxidation state of O increases from 0 to +2. Thus, the O is oxidized in the given reaction.