Chemical Thermodynamics

What is Hydration Enthalpy?

The quantity of energy produced when a one mole of ions undergoes hydration is hydration energy or hydration enthalpy. Hydration is a kind of solvation. Hydration energy is a form of dissolution of energy where the solvent is water. One of the most challenging components of structural prediction is determining the number of hydration energies. […]

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Chemical Thermodynamics, Chemistry, Class 11, Enthalpy, entropy, IIT JEE

Third Law of Thermodynamics

Standard energy change of formation is known as a change in enthalpy when one mole of a substance is produced in a standard state from its pure elements in the same conditions. It is also referred to as standard enthalpy of formation and is equal to standard enthalpy change of formation of products and reaction.

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Chemical Thermodynamics, Chemistry, Class 11, Enthalpy, entropy, IIT JEE

Standard Entropy of Formation of a Compound

What exactly is standard entropy? The standard entropy (S°) is the absolute entropy of a pure material at 25°C (298 K) and 1 atm pressure. At any temperature over 0°K, the conventional entropies of all substances, whether elements or compounds, are always positive. ΔS° = Σ S°products – Σ S°reactants Where ΔS° is the standard

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Chemical Thermodynamics, Chemistry, Class 11, Enthalpy, entropy, IIT JEE

Psychrometer

Psychrometer is a device meant for determining relative humidity in the atmosphere by the reading and comparison of two thermometers: i.e. the dry-bulb and wet-bulb air temperatures. The psychrometer is a type of hygrometer. A psychrometer possesses many different uses both in the home and industry. Besides measuring relative humidity and weather forecasting, it can

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Chemical Thermodynamics, Chemistry, Class 11, Enthalpy, entropy, IIT JEE

Plots for Ideal and Non-Ideal Solutions

The ideal solution R & S is formed when R-S interactions in the solution are similar to the R-R and S-S interactions. It should be of an equal type of component that will interact with itself and the other component. The ideal solution always obeys Raoult’s Law. It is the solution that doesn’t obey Raoult’s

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Chemical Thermodynamics, Chemistry, Class 11, Enthalpy, entropy, IIT JEE

Notes on Entropy

Entropy is a qualitative measure of the amount of energy of subatomic particles spreading out in a process, and it can be expressed in terms of a system’s statistical probability or other thermodynamic characteristics. Entropy is a thermodynamic variable used to describe the path of a process, such as whether it is a spontaneous process

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Chemical Thermodynamics, Chemistry, Class 11, Enthalpy, entropy, IIT JEE

Negentropy

The entropy of the reverse transition is produced via negentropy. Production of entropy is a positive value according to the second rule of thermodynamics. The beneficial creation of entropy (negentropy) is the difference between the entropy produced by direct and reverse transformations. Negentropy is the opposite of entropy. It implies that things are getting more

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Chemical Thermodynamics, Chemistry, Class 11, Enthalpy, entropy, IIT JEE

Measurement of ∆U and ∆H

Introduction The heat evolved at constant volume, and heat change at constant pressure is measured using a calorimeter. The process is called Calorimetry. Bomb Calorimeter is used to measure the ∆U, while a coffee calorimeter is used to measure ∆H. Calorimetry also helps in determining if a reaction is endothermic or exothermic. Now let us

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Chemical Thermodynamics, Chemistry, Class 11, Enthalpy, entropy, IIT JEE

Liquids: Viscosity

Introduction A fluid’s viscosity is a measurement of its resistance to deformation at a specific rate. It corresponds to the informal sense of “thickness” in liquids: syrup, for example, has a higher viscosity than water. The internal frictional force between adjacent layers of fluid in relative motion is measured by viscosity. If a viscous fluid

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Chemical Thermodynamics, Chemistry, Class 11, Enthalpy, entropy, IIT JEE