Physical Chemistry

– For reactions involving solids and liquids only the change in volume (ΔV) is very small and the term P × ΔV is negligible. For such reactions, the Change of Enthalpy of Reaction ΔH is equal to ΔE. Enthalpy of Reaction – Thermochemical measurements are made either at (a) constant …

MCQ on the First Law of Thermodynamics – In this subject, you will find 50 questions and answers MCQ on the First law of Thermodynamics 1. The first law of thermodynamics is_______ (a) the total energy of an isolated system remains constant though it may change from one form to …

Adiabatic Expansion of an Ideal Gas – A process carried in a vessel whose walls are perfectly insulated so that no heat can pass through them, is said to be adiabatic. – In the adiabatic process there is no heat exchange between a system and surroundings, and q = 0. …

Molar Heat Capacity – By heat capacity of a system, we mean the capacity to absorb heat and store energy. – As the system absorbs heat, it goes into the kinetic motion of the atoms and molecules contained in the system. – This increased kinetic energy raises the temperature of …

– Enthalpy (H) is the total heat content of a system at constant pressure and is equivalent to the internal energy E plus the PV energy. Enthalpy of A System – In a process carried at constant volume (say in a sealed tube), the heat content of a system is …

– The phenomenon of producing a lowering of temperature when a gas is made to expand adiabatically from a region of high pressure into a region of low pressure is known as the Joule-Thomson Effect or Joule-Kelvin Effect Joule-Thomson Effect – Joule and Thomson (later Lord Kelvin) showed that when …

– The first law of Thermodynamics states that The total energy of an isolated system remains constant though it may change from one form to another. Internal Energy – A thermodynamic system containing some quantity of matter has within itself a definite quantity of energy. – This energy includes not …

– In physics, mechanical work is defined as force multiplied by the distance through which the force acts. – In elementary thermodynamics, the only type of work generally considered is the work done in the expansion (or compression) of a gas Nature of Heat and Work  – When a change …

– Thermodynamic Processes involve the change of conditions (temperature, pressure, and volume). Thermodynamic Processes – When a thermodynamic system changes from one state to another, the operation is called a Process. – Thermodynamic Processes involve the change of conditions (temperature, pressure, and volume). – The various types of thermodynamic processes …

What is Thermodynamics? – Thermodynamics is The study of the flow of heat or any other form of energy into or out of a system as it undergoes a physical or chemical transformation. – In studying and evaluating the flow of energy into or out of a system, it will …

Hybridization and Shapes of Molecules – In the previous subject, we talked about the concept of Hybridization and the types of Hybridization, but in this subject, we will talk about Hybridization and Shapes of Molecules. – Diatomic molecules must all be invariably linear but tri-and tetra-atomic molecules have several possible …

– In this subject, we will discuss the Hybridization: Definition, Types, Rules, and Examples – While the formation of simple molecules could be explained adequately by the overlap of atomic orbitals, the formation of molecules of Be, B, and C present problems of greater magnitude having no solution with the …

– In this subject, we will discuss free download of Physical Chemistry book, 3rd edition by Robert G. Mortimer The Preface of Physical Chemistry book    – The book is divided into four parts: – The first part focuses on the macroscopic properties of physical systems. It begins with the …

– In this subject, we will discuss free download of Fundamentals of Electrochemistry book by V.S. Bagotsky The Preface of Fundamentals of Electrochemistry book – Two very important fields of natural science—chemistry and the science of electricity— matured and grew vigorously during the first half of the nineteenth century. Electrochemistry …

Bond Formation (Valence Bond Theory) – Bond formation between atoms to give chemical compounds can be interpreted admirably in terms of the orbital theory of atomic structure. – Heitler and London believed that electron cloud of the valence orbital on one atom ‘overlaps’ the electron cloud of the other bonding …

MCQ on Chemical bonding – In this subject, you will find 50 questions and answers MCQ on Chemical bonding   1. The valency of an element is ___________ (a) the combining capacity of one atom of it (b) the number of bonds formed by its one atom( c) the number …

– In this subject, we will discuss the VSEPR Theory: definition, Postulates, limitations, and Predicting Shapes of Molecules. VSEPR Theory – The Lewis structure of a molecule tells us the number of pairs of electrons in the valence shell of the central atom. – These electron pairs are subject to …

– In this subject, we will discuss the Bond Dissociation Energy: Definition, Equation, Problems Bond Dissociation Energy  – Bond breaking can be quantified using the bond dissociation energy. – The bond dissociation energy is the energy needed to homolytically cleave a covalent bond. – The energy absorbed or released in …

– In this subject, we will discuss the Metallic Bonding: Definition, Properties, Examples, Explanation Metallic Bonding – The valence bonds that hold the atoms in a metal crystal together are not ionic, nor are they simply covalent in nature. – Ionic bonding is obviously impossible here since all the atoms …

– In this subject, we will discuss the Polar Covalent Bond: Definition, Properties, Examples Polar Covalent Bonds – In the H2 or Cl2 molecule, the two electrons constituting the covalent bond are equally shared by the two identical nuclei. – Due to the even distribution of (+) and (–) charge, …