According to Lambert-Beer law, when a beam of monochromatic radiation passes through any solution, the intensity of the beam reduces to some amount. Let if I0 is the intensity of incident beam and It is the intensity of transmitted beam, then the intensity of energy ...

According to the principle of photochemical activation, only that part of the light which is absorbed by any system can cause photochemical change or reaction. However this is not essential that every time, the energy which is absorbed by any system can bring about a ...

Today photochemistry has become one of the most powerful research tool. Compounds of different molecules are occurred through various photochemical reactions like CO₂, NH₃ and methane. Other examples of photochemical reactions are formation of O₃, smog, Vitamin D and many more. A new field in ...

Photochemistry is the branch of science which deals with chemical reactions, reactions which occurred by the absorption of light waves which are called photons of energy. Only the radiations which fall under the region 800 nm to 200 nm can cause such reactions. Also the ...

Entropy of real gases: We know that: (∂S / ∂P)T = - (∂V / ∂T)P ……………………. (1) is one of the Maxwell relations which can also be written as: dS – (∂V / ∂T) P) dP …………………. (2) Integrating between pressure P1 and P2 at constant tempearute T , we ...

Absolute entropies of solids: Entropy change for an infinitesimally small change of a state of a substance is given as: dS = dq / T If the changes take place at constant pressure, then, (∂S) P = (∂q) P / T Multiplying both the sides by ∂T, we will ...

The Nernst Heat Theorem Let us consider the Gibbs-Helmholtz equation which includes chemical reaction i.e.: ∆G - ∆H = T (∂ (∆G)/∂T) P ………………………………….. (1) Where ∆G -------> change in free energy ∆H -------> ...

Irreversible process: An Irreversible process is one in which heat is transferred through a finite temperature. Irreversible process is also known as spontaneous process because these processes take place at very fast rate. Examples of irreversible processes are as follows: 1) Relative motion with friction 2) Falling of the water from ...