chemical kinetics Flashcards
(13 cards)
rate eqn
an experimentally determined mathematical expression between the reaction rate and concentration of reactants
rate constant
a proportionality constant for a given reaction at a specified temperature
order of reaction
____ with respect to a reactant is the power to which its concentration is raised up to in the experimentally determined rate equation
overall order of reaction
overall order of reaction
sum of the orders of reaction with respect to the reactants
rate of reaction
change in concentration of the reactant/product per unit time
differentiate between instantaneous, initial and avg rate
instantaneous:
draw tangent at time = t of conc-time graph and find grad
initial:
draw tangent at time = 0 of conc-time graph and find grad
average:
total change in conc of rxnt/product / total time taken
half-life
time taken for the concentration of a reactant to be halved
why do we need to add water to the exp
to keep the total volume of the reaction mixture constant for the diff exp
initial concentration of the reactant in the reaction mixture is directly proportional to the volume used
activation energy
minimum energy the reacting particles must possess in order to overcome the energy barrier before the formation of products
conditions for effective collisions
reactants must collide in:
correct relative position
possess minimum amount of KE (Ea)
Ea used for:
overcoming repulsive forces between reacting particles when they approach one another
break bonds in the reacting particles
factors affecting rate of reaction
concentration for solns (pressure for gas)
surface area for solids
temperature
catalyst
when concentration increases… what happens to rate?
solns:
conc increase -> increase in no. of particles per unit volume -> increase in frequency of effective collisions -> rxn rate increases
gas:
pV=nRT
identify unchanged variables
and calculate using rate constant
