Explain reaction rate with definition.
Reaction Rate: The reaction rate is defined as the change in the concentration of a reactant or product in a unit time.
For a general reaction: aA+bB→pP+qQ
r=-1a-d[A]dt=-1bd[B]dt=1pd[P]dt=1qd[Q]dt
Explain the difference between instantaneous rate of reaction and average rate of a reaction.
Thermodynamic feasibility of the reaction alone cannot decide the rate of the reaction. Explain with the help of one example.