Chapter 10, Problem 10.9P

(a)

Interpretation Introduction

Interpretation: For the given experiment, the rate-limiting step and an adsorption-surface reaction-desorption mechanism have to be proposed.

Concept Introduction:

The phenomenon of adsorption-surface reaction-desorption will be of the form:

$\begin{array}{l}{\text{A}}_{\text{2}}\text{+}\text{2S}\stackrel{}{\rightleftarrows }\text{2A}\text{.S}\Rightarrow \text{Adsorption}\\ \text{B}\text{+}\text{A}\text{.S}\stackrel{}{\to }\text{C}\text{.S}\Rightarrow \text{Surface-}\text{Reaction}\\ \text{C}\text{.S}\stackrel{}{\to }\text{C+}\text{S}\Rightarrow \text{Desorption}\end{array}$

The reactant A is adsorbed on the surface S. The adsorbed reactant A will react with the reactant B and forms the product C on the same surface. The product C will then get desorbed from the surface.

Rate-limiting step:

The slowest step of a reaction mechanism is the rate-determining step. The rate determining step is also known as the rate-controlling or rate-limiting step.

In the expression of rate law and rate limiting step, the concentration of the reactant species have to be given in terms of partial pressures which is represented as follows:

${\text{C}}_{\text{c}}\stackrel{}{\to }{\text{P}}_{\text{c}}$

(b)

Interpretation Introduction

Interpretation: The given thought of an automobile engineer has to be argued as agreed or disagreed.

Concept Introduction:

In 1981, the U.S government put forth the plan for automobile manufacturers to reduce emissions from automobiles. The plan was to reduce the amount of emission of each of the following gases over each year.

Hydrocarbons

$\text{CO}$-Carbon monoxide

$\text{NO}$- Nitrogen monoxide.

A scheme has been proposed to remove the hazardous $\text{NO}$. According to that scheme, the removal of $\text{NO}$ can be achieved by reducing $\text{NO}$ using unburned carbon monoxide over a solid catalyst.

The reduction reaction is:

$\text{CO}\text{+}\text{NO}\stackrel{\text{Catalyst}}{\to }\text{Products}\left({\text{N}}_{{}_{\text{2}}}\text{,}{\text{CO}}_{{}_{\text{2}}}\right)$

Catalytic reactor:

It is a cylindrical tube like reactor with a fixed bed. The cylindrical tube will be filled with catalyst pellets along with the reactants. The reactants react with the catalyst and flow through the bed and thereby get converted into products.

The major types of reactors are:

CSTR means Continuous stirred-tank reactor. It serves as a common model for a chemical reactor in chemical engineering. It is a mathematical model that works for all types of fluids, liquids, gases and slurries. Prefect mixing of substances can be achieved from this reactor by its action of continuous stirring.

PFR means Plug flow reactor: This reactor model enable to study about the continuous flowing systems in cylindrical geometry.

(c)

Interpretation Introduction

Interpretation: If everyone were driving a hybrid by 2018 and a driverless car by 2020, then the relevance of the problem has to be determined.

Concept Introduction:

In 1981, the U.S government put forth the plan for automobile manufacturers to reduce emissions from automobiles. The plan was to reduce the amount of emission of each of the following gases over each year.

Hydrocarbons

$\text{CO}$-Carbon monoxide

$\text{NO}$- Nitrogen monoxide.

A scheme has been proposed to remove the hazardous $\text{NO}$. According to that scheme, the removal of $\text{NO}$ can be achieved by reducing $\text{NO}$ using unburned carbon monoxide over a solid catalyst.

The reduction reaction is:

$\text{CO}\text{+}\text{NO}\stackrel{\text{Catalyst}}{\to }\text{Products}\left({\text{N}}_{{}_{\text{2}}}\text{,}{\text{CO}}_{{}_{\text{2}}}\right)$