How does heat affect a chemical reaction?

1 Answer
Jun 27, 2018

see below

Explanation:

the termodinamic possibility of a chemical reaction (#Delta G#) is controlled by Gibbs' law.
#Delta G = Delta H- T xx Delta S#
where:

#Delta H# is the difference of enthalpy between products and reagents. this difference is due to the force of the bonds, and is almostindipendent by the temperature.

#Delta S# is the difference of of Entropy between products and reagents. This difference is due to the Volume of the products and of the reagents and by their aggregation state. If doesn't change the aggregation state #Delta S# is almost indipendent by the temperature.

T is the absolute temperature. Hence the termodinamic possibility of a chemical reaction is due overall by the valour of the product between tempearure and the difference of entropy.

If #Delta G# > 0 the reaction doesn't occurr or occurr just a little
if #Delta G#< 0 the reaction occurrs
if #Delta G# = 0 you have the equilibrium between reagents and products according to
#Kp =e^((-Delta G)/(RT))#
where Kp is the costant of equilibrium and R the universal costant of ideal gases

Also if #Delta G#< 0 the reaction can no occur by cinetic problems and because a reaction canoccurr, it is necessary overcome the activation energy, that depends by the force of chemical bonds in the reactants.
Speed constant is #K= K° xx e ^((-Delta Ea)/(RT))#
Henceby increasing T every reaction is faster