Equations
What is the rate equation?
R=k[A]^x[B]^y
What is the Gibbs equation?
∆G = ∆H - T • ∆S
The rate of change of a product in a chemical reaction.
Reaction rate
Why does higher temperature increase the chemical reaction rate?
Because the reactant molecules (or atoms) move faster, increasing the chance for a collision.
A series of chemical equations that tells the step-by-step process by which a chemical reaction occurs.
Reaction mechanism
R = ∆ [product] ∆t = - ∆ [reactant] / ∆t
Rate of chemical reaction equation
What speeds up the reaction rate without actually getting used up in the chemical reaction?
Catalysts
What is determined by the variation of the rate constant with temperature?
The temperature dependence of reaction rate.
What happens when you decrease the concentration in a chemical reaction?
Decreasing concentration decreases the chemical reaction rate because there are fewer reactant molecules (or atoms) to collide with one another.
The point at which both the forward and reverse reactions in a chemical equation have equal rates.
Chemical equilibrium
What is the equation for the standard change in enthalpy for a reaction?
∆Hº = ∑∆Hfº(products) - ∑∆Hfº(reactants)
Catalysts that have the same phase as at least one of the reactants.
Homogeuos catalysts
General rule
What happens to the rate of chemical reactions for every 10º increase in temperature?
The rate of chemical reactions double.
What happens when you increase the surface area of a reactant? Why?
Increasing the surface area of a reactant increases the reaction rate because molecules (or atoms) of the reactant can more easily mingle with the molecules (or atoms) of the other reactants.
The energy necessary to start a chemical reaction
Activation energy
What is the equation for the standard change in entropy for a reaction?
∆Sº = ∑∆Sfº(products) - ∑∆Sfº(reactants)
Catalysts that are in a different phase than the reactants.
Heterogeneous catalysts.
A measure of the disorder that exists in any system
Entropy
What law states that enthalpy is a state of function?
Hess's law.
What does the second law of thermodynamics state?
The entropy of the universe must always either increase or decrease or remain the same. It can never decrease.
What is the equation in Gibbs free energy for a reaction?
∆Gº = ∑∆Gfº(products) - ∑∆Gfº(reactants)
Second law of thermodynamics in terms of ∆S?
∆S universe ≥ 0
What is the energy change that accompanies a chemical reaction called?
Change in enthalpy
What is the strength of a chemical bond called?
Bond energy
When a stress (such as a change in concentration, pressure, or temperature) is applied to an equilibrium, the reaction will shift in a way that. relieves the stress and restores equilibrium.
La Châtelier's principle