Documentation:CHBE Exam Wiki/2.4 - Degrees of Freedom for Reactive Systems

2.4 – Degrees of Freedom for Reactive Systems

2.4.0 – Learning Objectives

By the end of this section you should be able to:

number Calculate degrees of freedom using extent of reaction or atomic species for reactive systems

2.4.1 – Introduction

As you learned in Module - 1, degrees of freedom(DOF) can save you precious time and resources. It is very important to perform a DOF analysis before calculating the solution to any problem.

2.4.2 – Degrees of Freedom for Extent of Reaction

The DOF of extent of reaction can be calculated by using the following equation:

$DOF={\text{number of unknown varibles}}+{\text{number of independant reactions}}-{\text{number of independant reactive species}}-{\text{number of independant nonreactive species}}-{\text{number of other equations relating unknown varibles}}$

This will equation will inform you if the problem is solvable.

2.4.3 – Degrees of Freedom for Atomic Species Balances

The DOF of atomic species balances can be calculated by using the following equation:

$DOF={\text{number of unknown varibles}}-{\text{number of independant atomic species balances}}-{\text{number of molecular balances on independent nonreactive species}}-{\text{number of other equations relating unknown varibles}}$

This will equation will inform you if the problem is solvable.