Answer
Reaction rate: rate at which the concentration of a reactant or product changes over time
Initial Rate: reaction rate at the instant the reaction begins
Average Rate: reaction rate over an interval of time
Instantaneous rate: reaction rate at an instant in time
The initial rate is usually the fastest.
Work Step by Step
Definitions were provided in the textbook.
The initial rate is usually the fastest because the concentration of reactants is greatest before any reaction has taken place, and the reaction rate is directly proportional to the concentration of reactants.
