Chem 2 Exam 2

Front 1

chemical kinetics

Back 1

study of reaction rates.
can give insights into whats happening at the molecular level in a reaction

Front 2

reaction rate

Back 2

increase in molar concentration of a product of a reaction per unit time
OR
decrease in molar concentration of a reactant per unit time

Front 3

initial rate

Back 3

fastest rate in a reaction

Front 4

reaction rate proportions

Back 4

reactants
# of effective molar collisions
1 / activation energy
catalyst
reaction temperature
surface area of solid reactant or catalyst

Front 5

activated complex(transition state)

Back 5

an unstable grouping of atoms that can break up to form products.
symbol: double dagger

Front 6

activation energy

Back 6

minimum energy of collision required for 2 molecules to react

Front 7

progress of reaction

Back 7

has nothing to do with time
lower energy tends to be more stable

Front 8

rate constant

Back 8

a proportionality constant that relates rate and reactant concentrations

Front 9

rate law

Back 9

indicates how the rate of reaction changes as reactants change

Front 10

half life

Back 10

time required for the reactant to decrease to one-half of its initial value

Front 11

reaction mechanism

Back 11

the pathway the reaction takes

Front 12

elementary reactions

Back 12

individual steps in the larger overall reaction

Front 13

unimolecular

Back 13

rxn only involves one reactant molecule (falls apart)

Front 14

bimolecular

Back 14

rxn involves the collision of 2 reactant molecules

Front 15

termolecular

Back 15

rxn requires the collision of 3 reactant molecules.
all 3 things happen at the same time

Front 16

dynamic equilibrium

Back 16

consists of forward rx, in which reactants react to give products, amd a reverse rxn, in which products react to give original reactants

Front 17

chemical equilibrium

Back 17

(dynamic equilibrium) is the state reached by a rxn mixture when the forward rates = reverse rates

Front 18

law of mass action

Back 18

dictates that a rxn will always settle into an equilibrium where the equilibrium-constant expression equals K (for particular rxn at given T and P), regardless of the initial concentration of the reactants and/or products that are mixed together

Front 19

K(overall)

Back 19

= K (a《》x) × K (x 《》b)

Front 20

heterogeneous equilibrium

Back 20

reactants and products in more than one phase

Front 21

le chatelier's principle

Back 21

when a system in a chemical equilibrium is disturbed by a change of concentration (reactant or product), volume (pressure), or temperature, the equilibrium will shift in a way that tends to counteract this change.

Front 22

effect of temp change

Back 22

endothermic adds heat to reactant
exothermic adds heat to product

Front 23

catalyst

Back 23

a substance that increases the rate of a rxn but is not consumed by it
has no effect on equilibrium composition, wont make something happen that wouldnt in the first place