Topic 2a- Kinetics (DRL and IRL) Flashcards
kinetics
how fast chemical processes occur (eg rate of reaction)
higher concentration of reactants will do what to products
decrease
what is the high point on a energy graph
transition process
reactions that depend on concentrations and rate are called
differential rate law
concentration that depend on time are called
integrated law rates
what letter is rate constant? what does it mean?
-k
-constant for a specific reaction under a set of conditions
molecules are likey to collide as the ________ of reactants increase
concentration
factors that affect reaction rates
-temp- higher temp= greater energy
-catalysts- speed up reaction
which bump will be higher or lower when it comes to fast and slow rates
-slow= higher bump
-fast- lower bump
average rate formula
change in conc (Cf-Ci)/ change in time (Tf-Ti)
Instantaneous rate
rate of change over a specific moment in time
when writing rate expressions what do we need to do for reactants
put a negative- remember that decomposition will still have negative
rate law formula, what are the end steps after finding the values
-rate=k[a][b]
-use the trial concentration= k[trial][trial]
-isolate k
-use overall order units
tips for finding 0th, 1st, 2nd order
-0th- rate stays constant, m/s, [A]t on graph, -k downwards
-1st- rate doubles, s-1, ln[A] on graph, -k slope downwards
-2nd- sqaured, m-1 s-1, +k slope upwards
do the lines have to be linear in order to be an order?
yes, because the equation is = y=mx+b
what is the integrated law equation for 0th order
[a]t=-kt+[a]o
-same as 1st order on data sheet but take of ln
if one of the two reactants does not change over time, what do we use? what is the forumla
pseudo first order
- rate= k’[A]
what does half life mean
-the time required for one half of a reactant to react.
-[a] at 1/2 is equal to one half of the original, so [a]t= 0.5 [a]o
half life formulas for 0th, 1st, and 2nd order
-oth- [a]o/2k
1st- 0.693/k
2nd- 1/k[a]0
