Question

define the following reactions :-
(1) Exothermic reaction
(2) photochemical reaction
(3) Electrochemical reaction
(4) reversible reaction​

Answer 1

1.An exothermic process releases heat, causing the temperature of the immediate surroundings to rise. An endothermic process absorbs heat and cools the surroundings.

2.A Photochemical reaction is a reaction which takes place when a chemical process absorbs light energy as its energy source.

3.An electrochemical reaction is a process in which electrons flow between a solid electrode and substance, such as an electrolyte. This flow triggers an electric current through the electrodes, causing the reaction to liberate or absorb heat

4.In principle, all chemical reactions are reversible reactions . This means that the products can be changed back into the original reactants .

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Answer 2

$\sf{Answer}$

1. An exothermic reaction is a reaction in which energy is released in the form of light or heat. Thus in an exothermic reaction, energy is transferred into the surroundings rather than taking energy from the surroundings as in an endothermic reaction. In an exothermic reaction, change in enthalpy ( ΔH) will be negative.
2. Photochemical reaction, a chemical reaction initiated by the absorption of energy in the form of light. ... The consequence of molecules' absorbing light is the creation of transient excited states whose chemical and physical properties differ greatly from the original molecules.
3. Anne Marie Helmenstine, Ph. D. A reversible reaction is a chemical reaction where the reactants form products that, in turn, react together to give the reactants back. Reversible reactions will reach an equilibrium point where the concentrations of the reactants and products will no longer change.
4. An electrochemical reaction is a process in which electrons flow between a solid electrode and substance, such as an electrolyte. This flow triggers an electric current through the electrodes, causing the reaction to liberate or absorb heat.

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