Chapter 7, Problem 7.30AP

(a)

Interpretation Introduction

Interpretation:

The balanced equation for the combustion of octane is to be determined.

Concept Introduction:

Enthalpy $\left(H\right)$: it is the total amount of heat in a particular system.

The value of heat formed in a reaction $\text{ΔH}$ is calculated by the formula,

$\text{ΔH=}{{\displaystyle \sum \left(BondDissociationEnergy\right)}}_{\left(\text{reactants}\right)}-{{\displaystyle \sum \left(BondDissociationEnergy\right)}}_{\left(\text{products}\right)}$

If the value obtained for $\text{ΔH}$ in a reaction is positive then it is an endothermic reaction whereas the value obtained for $\text{ΔH}$ is negative it is an exothermic reaction.

Chemical equation is the representation of a chemical reaction, in which the reactants and products of the reactions are represented left and right side of an arrow respectively by using their respective chemical formulas.

Combustion is the process of burning of a compound; in which the compound reacts with excess of oxygen.

(b)

Interpretation Introduction

Interpretation:

The sign of change in enthalpy for the combustion of octane is to be determined.

Concept Introduction:

Enthalpy $\left(H\right)$: it is the total amount of heat in a particular system.

The value of heat formed in a reaction $\text{ΔH}$ is calculated by the formula,

$\text{ΔH=}{{\displaystyle \sum \left(BondDissociationEnergy\right)}}_{\left(\text{reactants}\right)}-{{\displaystyle \sum \left(BondDissociationEnergy\right)}}_{\left(\text{products}\right)}$

If the value obtained for $\text{ΔH}$ in a reaction is positive then it is an endothermic reaction whereas the value obtained for $\text{ΔH}$ is negative it is an exothermic reaction.

Combustion is the process of burning of a compound; in which the compound reacts with excess of oxygen.

(c)

Interpretation Introduction

Interpretation:

The energy for the released during the combustion of one mole of octane is to be determined.

Concept Introduction:

Enthalpy $\left(H\right)$: it is the total amount of heat in a particular system.

The value of heat formed in a reaction $\text{ΔH}$ is calculated by the formula,

$\text{ΔH=}{{\displaystyle \sum \left(BondDissociationEnergy\right)}}_{\left(\text{reactants}\right)}-{{\displaystyle \sum \left(BondDissociationEnergy\right)}}_{\left(\text{products}\right)}$

If the value obtained for $\text{ΔH}$ in a reaction is positive then it is an endothermic reaction whereas the value obtained for $\text{ΔH}$ is negative it is an exothermic reaction.

Combustion is the process of burning of a compound; in which the compound reacts with excess of oxygen.

From its given mass is,

$\text{Number of moles}\text{=}\frac{\text{Given}\text{mass}}{\text{Molecular}\text{mass}}$

(d)

Interpretation Introduction

Interpretation:

The number of moles and the amount of octane required for the releasing of $450.0kcal$ heat while burning is to be determined.

Concept Introduction:

Enthalpy $\left(H\right)$: it is the total amount of heat in a particular system.

The value of heat formed in a reaction $\text{ΔH}$ is calculated by the formula,

$\text{ΔH=}{{\displaystyle \sum \left(BondDissociationEnergy\right)}}_{\left(\text{reactants}\right)}-{{\displaystyle \sum \left(BondDissociationEnergy\right)}}_{\left(\text{products}\right)}$

If the value obtained for $\text{ΔH}$ in a reaction is positive then it is an endothermic reaction whereas the value obtained for $\text{ΔH}$ is negative it is an exothermic reaction.

Combustion is the process of burning of a compound; in which the compound reacts with excess of oxygen.

From its given mass is,

$\text{Number of moles}\text{=}\frac{\text{Given}\text{mass}}{\text{Molecular}\text{mass}}$

(e)

Interpretation Introduction

Interpretation:

The energy for the released during the combustion of $17.0g$ of octane is to be determined.

Concept Introduction:

Enthalpy $\left(H\right)$: it is the total amount of heat in a particular system.

The value of heat formed in a reaction $\text{ΔH}$ is calculated by the formula,

$\text{ΔH=}{{\displaystyle \sum \left(BondDissociationEnergy\right)}}_{\left(\text{reactants}\right)}-{{\displaystyle \sum \left(BondDissociationEnergy\right)}}_{\left(\text{products}\right)}$

If the value obtained for $\text{ΔH}$ in a reaction is positive then it is an endothermic reaction whereas the value obtained for $\text{ΔH}$ is negative it is an exothermic reaction.

Combustion is the process of burning of a compound; in which the compound reacts with excess of oxygen.