Chapter 9, Problem 9.40EP

(a)

Interpretation Introduction

Interpretation:

The given reaction is endothermic or exothermic has to be discussed.

    ${\text{CaCO}}_{\text{3}}\text{ + heat}\stackrel{}{\to }{\text{ CaO + CO}}_{\text{2}}$

Concept Introduction

Endothermic Reactions:

The chemical reaction in which heat energy is absorbed known as endothermic reaction.  If the energy required to break the bond is greater than the energy released, then it is said to be endothermic reaction. 

Examples for endothermic reactions:

• Melting ice cubes.
• Evaporation of water.
• Producing sugar from photosynthesis.

(b)

Interpretation Introduction

Interpretation:

The given reaction is endothermic or exothermic has to be discussed.

    ${\text{N}}_{\text{2}}{\text{ + 3H}}_{\text{2}}\stackrel{}{\to }{\text{ 2NH}}_{\text{3}}\text{+ heat}$

Concept Introduction:

Exothermic Reactions:

The chemical reaction in which heat energy is released known as exothermic reaction.  The chemical bond will determine whether the reaction is exothermic or endothermic.  If the energy released by bond formation is greater than the energy required to break the bond, then the reaction is said to exothermic.

Examples for exothermic reaction:

• Making ice cubes.
• Formation of snow in clouds.
• Condensation of rain from water vapour.
• Rusting iron.
• Burning sugar.

(c)

Interpretation Introduction

Interpretation:

The given reaction is endothermic or exothermic has to be discussed.

    ${\text{CO + 3H}}_{\text{2}}\text{+ heat }\stackrel{}{\to }{\text{ CH}}_{\text{4}}{\text{+ H}}_{\text{2}}\text{O}$

Concept Introduction:

Endothermic Reactions:

The chemical reaction in which heat energy is absorbed known as endothermic reaction.  If the energy required to break the bond is greater than the energy released, then it is said to be endothermic reaction.

Examples for endothermic reactions:

• Melting ice cubes.
• Evaporation of water.
• Producing sugar from photosynthesis.

(d)

Interpretation Introduction

Interpretation:

The given reaction is endothermic or exothermic has to be discussed.

     ${\text{2N}}_{\text{2}}{\text{+ 6H}}_{\text{2}}\text{O + heat}\stackrel{}{\to }{\text{ 4NH}}_{\text{3}}{\text{+ 3O}}_{\text{2}}$

Concept Introduction:

Endothermic Reactions:

The chemical reaction in which heat energy is absorbed known as endothermic reaction.  If the energy required to break the bond is greater than the energy released, then it is said to be endothermic reaction. 

Examples for endothermic reactions:

• Melting ice cubes.
• Evaporation of water.
• Producing sugar from photosynthesis.