Chapter 10, Problem 14CI

(a)

Interpretation Introduction

Interpretation : A balanced chemical equation for the combustion of octane needs to be determined.

Concept Introduction : In a balanced chemical reaction, there are same number of constituent atoms in both sides of the reaction arrow.

The enthalpy of reaction can be defined as the energy change during chemical reaction. The value is positive for an endothermic and negative for an exothermic reaction. If the energy is released in a reaction, the reaction is exothermic and if it is evolved, the reaction is endothermic.

(b)

Interpretation Introduction

Interpretation : The amount of energy produced in kJ from octane in one tank.

Concept Introduction : In the chemical reaction, reactant molecules react to form products. The mass of a substance is related to its number of moles and molar mass as follows:

  $n=\frac{m}{M}$

Here, m is mass and M is molar mass.

Also, 1 mole of a substance contain $6.023\times {10}^{23}\text{ atoms}$ .

The enthalpy of reaction can be defined as the energy change during chemical reaction.

(c)

Interpretation Introduction

Interpretation : The number of molecules of octane present in 1 tank of fuel needs to be calculated.

Concept Introduction : In the chemical reaction, reactant molecules react to form products. The mass of a substance is related to its number of moles and molar mass as follows:

  $n=\frac{m}{M}$

Here, m is mass and M is molar mass.

Also, 1 mole of a substance contain $6.023\times {10}^{23}\text{ atoms}$ .

The enthalpy of reaction can be defined as the energy change during chemical reaction.

(d)

Interpretation Introduction

Interpretation : The mass of carbon dioxide produced from the combustion of fuel if the car covers 24500 miles in a year.

Concept Introduction : From the number of moles, mass can be calculated as follows:

  $m=n\times M$

Here, n is number of moles and M is molar mass.

From the distance travelled, the volume of fuel consumed can be calculated from its mileage.