differences between a photochemical reaction and a thermochemical reaction - Chemistry - Chemical Kinetics

Question

differences between a photochemical reaction and a
thermochemical reaction?

Nayan Kumar Singh · Accepted Answer

THERMOCHEMICAL REACTIONS :-

These reactions involve absorption or evolution of
heat
They can take place even in absence of
light i e dark

Temperature has significant effect
on the rate of a thermochemical reaction
The free energy change
âˆ†G of a thermochemical reaction is always
negative
They are accelerated by the presence
of a catalyst
PHOTOCHEMICAL REACTIONS
:-
These reactions involve absorption
of light
The presence of light is the primary
requisite for the reaction to take place
Temperature has very little effect
on the rate of a photochemical reaction Instead, the intensity of
light has a marked effect on the rate of a photochemical
reaction
The free energy change
âˆ†G of a photochemical reaction may not be
negative
Some of these are initiated by the
presence of a photosensitizer However a photosensitizer acts in a
different way than a catalyst

differences between a photochemical reaction and a thermochemical reaction?