Chapter 18 - Reaction Rates And Equilibrium Flashcards
How is the rate of a chemical reaction expressed?
In chemistry, the rate of a chemical reaction, or the reaction rate, is usually expressed as the change in the amount of reactant or product per unit time.
Rate
A measure of how much something changes within a specified amount of time.
Activation energy
The minimum energy that colliding particles must have in order to react.
What four factors influence the rate of a chemical reaction?
Factors that can affect the rate of a chemical reaction are temperature, concentration, particle size, and the use of a catalyst.
Reversible reaction
One in which the conversion of reactants to products and the conversion of products to reactants occur at the same time.
Chemical equilibrium
The rates of the forward and reverse reactions are equal.
Equilibrium position
The relative concentration of the reactants and products at equilibrium.
Free energy
The energy that is available for work.
Spontaneous reaction
Exo: occurs naturally and favors the formation of products at the stated conditions.
Non-spontaneous reaction
Does not favor the formation of products at the stated conditions.
What are two characteristics of spontaneous reactions?
Spontaneous reactions produce large amounts of product and release free energy.
Entropy
A measure of the disorder of a system.
Low of disorder
The natural tendency is for systems to move in the direction of increasing disorder or randomness.
What part does entropy play in a reaction?
Reactions in which entropy increases as reactants form products tend to be favored.
What two factors determine whether a reaction is spontaneous?
The size and direction of enthalpy changes and entropy changes together determine whether a reaction is spontaneous.
