Collisions Flashcards
collision model
A model based on the idea that molecules must collide in order to react; used to account for the observed characteristics of reaction rates
activation energy
The threshold energy that must be overcome to produce a chemical reaction
catalyst
A substance that speeds up a reaction without being consumed
enzymes
Large molecules, usually proteins, that catalyze biological reactions
equilibrium
A dynamic reaction system in which the concentrations of all reactants and products remain constant as a function of time
“exact balancing of two processes, one of which is the opposite of the other.”
chemical equilibrium
A dynamic reaction system in which the concentrations of all reactants and products remain constant as a function of time
law of chemical equilibrium
A general description of the equilibrium condition; it defines the equilibrium expression
equilibrium expression
The expression (from the law of mass action) equal to the product of the product concentrations divided by the product of the reaction concentrations, each concentration having first been raised to a power represented by the coefficient in the balanced equation
equilibrium constant (k)
The value obtained when equilibrium concentrations of the chemical species are substituted into the equilibrium expression
equilibrium position
A particular set of equilibrium concentrations
homogeneous equilibria
Equilibrium systems in which all reactants and products are in the same state
heterogeneous equilibria
Equilibrium systems involving reactants and/or products in more than one state
“position of a heterogeneous equilibrium does not depend on the amounts of pure solids or liquids present”
