Final Review

the study of how fast chemical reactions occur
what are the 4 important factors which affect rates of reaction?
1) reactant concentration
2) temperature
3) physical state
4) action of catalysts
how is the speed of a reaction measured?
by the change in concentration with time
the rate at any instant in time (instantaneous rate) is ______________ of the tangent to the curve.
the slope
the time taken for the concentration of a reactant to drop to half its original value
as temperature increases, rate ____________
what does the collision model state?
in order for molecules to react they must collide
t/f: all collisions lead to products
what do enzymes and catalysts do?
help get the right molecule orientation
what did Arrhenius say?
molecules must possess a minimum amount of energy to react
what is activation energy?
the minimum energy required to initiate a chemical reaction
t/f: a catalyst is used an regenerated
a catalyst changes the _________ of a chemical reaction
what are the 2 types of catalyst?
homogenous, heterogenous
catalysts _____________ the energy of activation
mass number is the sum of:
protons and neutrons
atomic number is
the number of protons
have the same number of protons and different numbers of neutrons
chemical equilibrium is the point at which:
the concentrations of all species are constant
what is the basis of Le Chatelier’s principle?
upon pressure increase, the reaction will proceed towards the side with the fewest number of gaseous molecules
what is an amphoteric substance?
one that can behave as an acid and a base
what is a conjugate base?
whatever is left of an acid after it donates a proton
what is a conjugate acid?
whatever is left of a base after it accepts a proton
buffer capacity
the amount of acid or base neutralized by the buffer before there is a significant change in pH
the loss of electrons
the gain of electrons
what happens at the cathode?
electrons flow from __________ to __________
anode, cathode