Difference Between Thermochemical and Photochemical Reaction:
The following are the points of difference between Thermochemical and Photochemical Reaction.
|Thermochemical Reaction||Photochemical Reaction|
|These reactions proceed with the absorption or evolution of heat.||These reactions proceed with the evolution or absorption of light.|
|These reactions can take place in the dark also.||The presence of light is essential for these reactions.|
|The temperature has a significant effect on these reactions and rate of reaction.||The temperature has no significant effect on these reactions but the intensity of light affects the rate of reaction.|
|ΔG is always negative for spontaneous reactions.||In photochemical reactions ΔG may or may not be negative for spontaneity. For example, ΔG is +ve for |
(i) Photosynthesis in plants
(ii) Ozonization of oxygen.
|Thermochemical activation is not of selective nature.||Photochemical activation is highly selective, i.e., absorbed photons of light excite only a particular atom, or molecule, or group of atoms, which then becomes the site for the photochemical reactions.|
Newtons Rings- Experimental Set-up and Applications
Waves- Types and Characteristics
Concept of Temperature (Zeroth Law)
Applications of Interference
Electrochemistry Notes From– Tamil Board