Answer to Question #65336 in Physical Chemistry for ella rose

Question

What factors influence the Rate of a Reaction?
What is an Exothermic Reaction? What is an Endothermic Reaction?

Answer 1

Solution:
According to the law of mass action (the speed of a chemical reaction at any given time is proportional to the concentrations of the reactants raised to a power equal to their stoichiometric coefficients) that the rate of chemical reactions affect the concentration of substances. In addition the reaction rate is also influenced by factors such as: the nature of the reactants; the surface area of the reactants; temperature (generally Van't Hoff, Arrhenius equation); the presence of a catalyst; the pressure (P).
The chemical reaction is accompanied by release of heat are called exothermic reactions. For such reactions enthalpy is negative:
ΔH < 0
A reaction in which heat is absorbed, called endothermic reactions. For them, the enthalpy is positive:
ΔH ˃ 0
Answer: In the chemical reaction rate influences: the concentration of substances; the nature of the reactants; the surface area of the reactants; temperature; the presence of a catalyst; the pressure.
Exothermic reaction – ΔH < 0 ;
Endothermic reaction – ΔH ˃ 0 .