Physical Chemistry studies the processes involving molecules and atoms in every chemical substance. It also studies the bulk systems. The subject uses the principles of Physics like motion, thermodynamics, quantum chemistry, chemical equilibria, force, energy, etc. to explain the various scientific processes. 

Here are some key concepts that physical chemistry has attempted to explain to date:

• • Physical chemistry deals with the intermolecular forces that are prevalent as an intrinsic property of all matters. It defines the plasticity, ultimate tensile strength as well as surface tension in fluids. 
  • A branch of physical chemistry is named chemical kinetics. This subject measures the rates of various chemical reactions. Kinetic chemistry is different from thermodynamics in the sense that it does not provide any information regarding the direction of a phenomenon. 

• Physical Chemistry classifies electrolytes based on their capacity to conduct electricity. Different types of ions are discussed in this subdivision. 

• We also get an idea of surface science when we learn physical chemistry. Surface science is the module that discusses chemical and physical processes that happen at the solid-liquid interface. 

• Another vital subtopic of physical chemistry is electrochemistry. This section makes us aware of the fundamental mechanisms that govern the relationship between a chemical process and an electric potential. 

• Thermodynamics is a major area of concern in the realm of physical chemistry. The laws of thermodynamics deal with the chemical and physical transformations of different states on the application of heat or work. 

• Physical Chemistry also defines the role of heat in affecting phase transformations like the boiling point, melting point, etc., of substances. Thus this branch where we study the energy transfer between two bodies is known as thermochemistry. 

• Quantum mechanics is a branch of physical chemistry that nurtures the field of study involving microscopic particles. This branch puts up the conclusions derived from fixed behavioral patterns of different matters as well as explains their properties in association with various forms of energy. 

• A relatively modern concept known as statistical mechanics helps us to understand the bulk matters. It is an opposite-field of study when compared to quantum mechanics. It explains the behavior of macroscopic elements through observational and empirical data and refrains from using any established laws. 

• The scope of physical chemistry even encompasses the topic of the colligative nature of solutions. This subject does not focus on the chemical portfolio of a solution. However, it takes into consideration the ratio of solvent and solute to study concepts like osmotic pressure, depression in freezing point, laws governing reduction in vapor pressure, etc. 

• Physical Chemistry even deals with the mechanism of electrochemical cells. These are the devices that use several chemical reactions to generate current. 

To assimilate the definition of physical chemistry, we need to recognize the scope of constituent branches of the subject. There are two branches: macroscopic and microscopic physical chemistry. 

Macroscopic chemistry only includes the particles and substances in its realm of study that are large enough to be perceived through vision. Optical instruments do not find extensive use under this branch. Some notable research fields under this head include vaporization enthalpy, enthalpy of fusion state, melting and boiling thermal points of substances in various states, etc. For more clarification regarding the scope of macroscopic chemistry, if we consider water this branch of study does not interfere with the molecular structure of water. It only studies the physical properties like boiling and melting points on a macroscopic scale. 

The microscopic scale studies the nature of particles that are invisible to the human naked eye. Magnification is required to execute research processes in this field. The atomic structure or crystal structure of elements and compounds is explained in microscopic chemistry. In a nutshell, this section is a definition of physical chemistry that deals with the properties of constituent particulate matters that form building blocks of macroscopic structures. 

Conclusion

From the above discussion, we have a clear response to the question – what is physical chemistry?

Physical Chemistry explains how substances behave on a macroscopic as well as the atomic stage. It also deals with various chemical processes. This information is crucial to recognizing the procedures involved in the formation of complex matters.