chapter 18 Flashcards
what are the units for rate?
moldm-3s-1
what is rate proportional to?
concentration of substance to power of order of reaction
what is k?
rate constant
dependant on temperature
what does a rate equation look like?
rate = k [A]^m[B]^n
how can you monitor rate?
gas collection
mass loss
colorimeter
what does conc time graph look like for zero order?
straight line
negative gradient
gradient is constant
what does conc time graph look like for first order?
rate proportional to constant
gradient decreases
can test by seeing if it has a constant half life
what is rate equal to on a graph?
k x [A]
what does rate conc graph look like for zero order?
straight horizontal line
k = y-intercept
what does rate conc graph look like for first order?
straight line through origin
k = gradient
what does rate conc graph look like for second order?
through origin going upwards in a curved line
what is the reaction mechanism?
series of steps that make up an overall reaction
what is the slowest step?
the rate-determining step
what is the rate-determining step made up of?
only of species that are in the rate equation
order = no. moles of species
how can you calculate k using graph?
k = Ae^(Ea/RT)
or
lnk = -Ea/RT = lnA
