The key difference between chemical kinetics and thermodynamics is that chemical kinetics refers to rates of chemical reactions, whereas thermodynamics refers to the direction of reactions.
The term chemical kinetics refers to the branch of physical chemistry that deals with the rates of chemical reactions. Thermodynamics refers to the branch of physical science that deals with the relations between heat and other forms of energy such as mechanical, electrical, or chemical energy.
CONTENTS
1. Overview and Key Difference
2. What is Chemical Kinetics
3. What is Thermodynamics
4. Chemical Kinetics vs Thermodynamics in Tabular Form
5. Summary – Chemical Kinetics vs Thermodynamics
What is Chemical Kinetics?
The term chemical kinetics refers to the branch of physical chemistry that deals with the rates of chemical reactions. It is also known as reaction kinetics. This term is described in contrast to thermodynamics. (Thermodynamics deal with the direction in which a process occurs).
What is Thermodynamics?
Thermodynamics can be described as the branch of physical science that deals with the relations between heat and other forms of energy such as mechanical, electrical, or chemical energy. This phenomenon explains the relationship between all energy forms. The main idea of thermodynamics is the association of heat with work done by or on a system.
Figure 01: A Generic Thermodynamic System
There are several important terms in thermodynamics, as listed below.
- Enthalpy – the total energy content of a thermodynamic system
- Entropy – a thermodynamic expression explaining the inability of a thermodynamic system to convert its thermal energy into mechanical energy
- Thermodynamic state – the state of a system at a given temperature
- Thermodynamic equilibrium – the state of a thermodynamic system being in equilibrium with one or more other thermodynamic systems
- Work – the amount of energy that is transferred to the surrounding from a thermodynamic system.
- Internal energy – the total energy of a thermodynamic system that is caused by the motion of molecules or atoms in that system.
Furthermore, thermodynamics includes a set of laws.
- Zeroth Law of Thermodynamics – When two thermodynamic systems are in thermal equilibrium with a third thermodynamic system, all three systems are in thermal equilibrium with each other.
- First Law of Thermodynamics – The internal energy of a system is the difference between the energy it absorbs from the surroundings and the work done by the system on the surrounding.
- Second Law of Thermodynamics – Heat cannot flow from a colder location to a hotter area spontaneously.
- Third Law of Thermodynamics – As a system approach absolute zero, all processes cease, and the entropy of the system becomes minimum.
What is the Difference Between Chemical Kinetics and Thermodynamics?
The term chemical kinetics refers to the branch of physical chemistry that deals with the rates of chemical reactions. Thermodynamics can be described as the branch of physical science that deals with the relations between heat and other forms of energy such as mechanical, electrical, or chemical energy. The key difference between chemical kinetics and thermodynamics is that chemical kinetics refers to rates of chemical reactions, whereas thermodynamics refers to the direction of the reaction.
Below is a summary of the difference between chemical kinetics and thermodynamics in tabular form for side by side comparison.
Summary – Chemical Kinetics vs Thermodynamics
Chemical kinetics and thermodynamics are important terms in physical chemistry. The key difference between chemical kinetics and thermodynamics is that chemical kinetics refers to rates of chemical reactions, whereas thermodynamics refers to the direction of reactions. In other words, chemical kinetics is important to determine the characteristics of the reaction, while thermodynamics is useful to predict the relations between heat and other forms of energy such as mechanical, electrical, or chemical energy
Reference:
1. “Chemical Kinetics.” Encyclopædia Britannica, Encyclopædia Britannica, Inc.
Image Courtesy:
1. “System boundary” By Original: Wavesmikey / Vectorization: Stannered – Own work based on: System-boundary.jpg (Public Domain) via Commons Wikimedia