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Physical Chemistry

Bond Enthalpy

Science > Chemistry > Chemical Thermodynamics and Energetics > Bond Enthalpy In this article, we shall study the concept of bond enthalpy. During the formation of the bond, energy is evolved or released. Thus the bond formation reaction is exothermic. Due to the release of energy molecule formed is at a low energy level and […]

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Physical Chemistry

Enthalpy Of Different Processes

Science > Chemistry > Chemical Thermodynamics and Energetics > Heat of Reaction Of Different Processes In this article, we shall study change in enthalpy for different chemical processes. Enthalpy of Formation (ΔfH° or ΔformationH°): The change in enthalpy of a chemical reaction at a given temperature and pressure, when one mole of the substance is formed […]

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Physical Chemistry

Heat of Reaction

Science > Chemistry > Chemical Thermodynamics and Energetics > Heat of Reaction The branch of chemistry which deals with the quantitative study of thermal or heat changes in various chemical reactions is known as thermochemistry. In this article, We shall discuss very important concept of chemistry i.e. heat of reaction. Thermochemical Equation: An equation which […]

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Physical Chemistry

Enthalpy of a System

Science > Chemistry > Chemical Thermodynamics and Energetics > Enthalpy of a System The enthalpy of system is defined as the sum of the internal energy of the system and energy that arises due to pressure and volume. It is denoted by letter H. Mathematically, H = U + PV Where, H = Enthalpy U […]

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Physical Chemistry

Laws of Thermodynamics

Science > Chemistry > Chemical Thermodynamics and Energetics > First Law of Thermodynamics In this article, we shall study the first law of thermodynamics and its application to different chemical processes. Zeroth Law of Thermodynamics: Statement: If two bodies (say A and B) are in thermal equilibrium of the third body (say C) then body […]

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Physical Chemistry

Concept of Maximum Work

Science > Chemistry > Chemical Thermodynamics and Energetics > Concept of Maximum Work According to the first law of thermodynamics, ΔU = q  +  W    In an isothermal process, ΔU  =   0, ∴   q   =   – W Therefore, all the heat absorbed by the system is utilized to do work. […]

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Physical Chemistry

Work Done in Chemical Process

Science > Chemistry > Chemical Thermodynamics and Energetics > Work Done in Chemical Process Pressure Volume Work: Consider an ideal gas having definite mass (say n moles) be enclosed in a cylinder fitted with weightless, frictionless, tightly fitted, movable piston. Let ‘A’ be the area of the cross-section of the cylinder. Let the gas expand […]

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Physical Chemistry

Concept of Internal Energy

Science > Chemistry > Chemical Thermodynamics and Energetics > Concept of Internal Energy The internal energy can be defined as the sum of all possible kinds of energies that a system possesses. Every chemical reaction is associated with heat change. Heat is either evolved or absorbed.  This is possible only when every substance involved in […]

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Physical Chemistry

Chemical Processes

Science > Chemistry > Chemical Thermodynamics and Energetics > Chemical Processes In this article, we shall discuss what is meant by process and different types of chemical processes. Process: It is the path or the operation by which a system changes from one state to another. A process causes a change in the value of […]

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Physical Chemistry

Introduction to Chemical Thermodynamics

Science > Chemistry > Chemical Thermodynamics and Energetics > Introduction Chemical Thermodynamics and its Scope: Energy stored in chemical substances is called chemical energy. Thermodynamics is the branch of science that deals with the different forms of energy, the quantitative relationships between them and the energy changes that occur in the physical and chemical process. […]