Exam 2 Flashcards
Chemical Kinetics
The area of chemistry concerned with the speeds, or rates, at which a chemical reaction occurs.
Thermodynamics
The scientific study of the interconversion of heat and other kinds of energy.
Collision Theory
The reaction rate directly propositional to the number of molecular collisions per second.
- create chemical reactions.
- faster at higher temperature.
Effective Collisions
A collision that results in a chemical reaction.
Activation Energy
(Ea)
The minimum amount of energy to begin a chemical reaction.
- molecules must be oriented to favor a reaction.
Activated Complex
when molecules collide in an effective collision.
also transition state.
Instantaneous Rate
The reaction rate at a specific time.
determined with slope.
Equilibrium
A state in which forward and reverse processes are occurring at the same rate.
Reaction Rate
How rapidly a reaction occurs.
- rate of change in concentration of reactants and products over time.
- generally decrease over the course of a reaction.
- use experiments to determine.
- overall rate of reaction is always positive.
Rate Law
An equation relating the rate of reaction to the concentrations of reactants.
rate = k[A]x[B]y
k = rate constant
Reaction Order
The sum of the powers to which all reactant concentrations appearing in rate law are raised.
x + y
rate = k[A]x[B]y
Units (k)
1 = s-1
2= M-1 s-1
3 = M-2 s-1
Initial Rate
The instantaneous rate at the beginning of a reaction.
M/s
Zero-Order Reaction
A constant rate, independent of reaction concentration.
Ex. rate = k
First-Order Reaction
A reaction whos rate depends on the reaction concentration raised to the 1st power.
Ex. rate = k[A]
Second-Order Reaction
a reaction whos rate depends on the concentration of one reactant raised to the 2nd power or on the product of the concentrations of two different reactions each raised to the first power.
Ex. rate = k[A]² or rate = k[A][B]
