Chapter 12, Problem 12.140MP

(a)

Interpretation Introduction

Interpretation:

After the given reaction time, the total pressure in the container has to be calculated.

Concept introduction:

Integrated rate law for a first order reaction:

A first order reaction is defined as the reaction whose rate depends only on the concentration of a single reactant raised to the first power.

$\text{Rate}\text{=}\text{-}\frac{\text{Δ}\left[\text{A}\right]}{\text{Δt}}\text{=}\text{k}\left[\text{A}\right]$

Integrated rate law for a first order reaction is given below

$\begin{array}{l}\text{ln}\frac{{\left[\text{A}\right]}_{\text{t}}}{{\left[\text{A}\right]}_{\text{0}}}\text{=}\text{-}\text{kt}\\ \text{where,}\\ \text{ln}\text{-}\text{natural}\text{logarithm}\\ {\left[\text{A}\right]}_{\text{0}}\text{-}\text{concentration}\text{of}\text{A}\text{at}\text{time}\text{t}\text{=}\text{0}\\ {\left[\text{A}\right]}_{\text{t}}\text{-}\text{concentration}\text{of}\text{A}\text{after}\text{time}\text{t}\\ \text{k}\text{-}\text{rate}\text{constant}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The initial rate at which the given reaction mixture absorbs heat has to be calculated.

Concept introduction:

Standard enthalpy of reaction:

The change in enthalpy that is associated with the formation of one mole of a substance from its related elements being in standard state is called standard enthalpy of formation (${\text{ΔH}}_{\text{f}}\text{°}$).  The standard enthalpy of formation is used to determine the standard enthalpies of compound and element.

The standard enthalpy of reaction is the enthalpy of reaction that takes place under standard conditions.

The equation for determining the standard enthalpies of compound and element can be given by,

${\text{ΔH°}}_{\text{reaction}}\text{=}{\displaystyle \sum {\text{nΔH°}}_{\text{f}}\text{(products)}}\text{-}{\displaystyle \sum {\text{mΔH°}}_{\text{f}}\text{(reactants)}}$

(c)

Interpretation Introduction

Interpretation:

After the given reaction time, the total amount of heat absorbed has to be calculated.

Concept introduction:

Integrated rate law for a first order reaction:

A first order reaction is defined as the reaction whose rate depends only on the concentration of a single reactant raised to the first power.

$\text{Rate}\text{=}\text{-}\frac{\text{Δ}\left[\text{A}\right]}{\text{Δt}}\text{=}\text{k}\left[\text{A}\right]$

Integrated rate law for a first order reaction is given below

$\begin{array}{l}\text{ln}\frac{{\left[\text{A}\right]}_{\text{t}}}{{\left[\text{A}\right]}_{\text{0}}}\text{=}\text{-}\text{kt}\\ \text{where,}\\ \text{ln}\text{-}\text{natural}\text{logarithm}\\ {\left[\text{A}\right]}_{\text{0}}\text{-}\text{concentration}\text{of}\text{A}\text{at}\text{time}\text{t}\text{=}\text{0}\\ {\left[\text{A}\right]}_{\text{t}}\text{-}\text{concentration}\text{of}\text{A}\text{after}\text{time}\text{t}\\ \text{k}\text{-}\text{rate}\text{constant}\end{array}$