Chemical Kinetics Flashcards
What is an exergonic reaction?
reaction with negative change in gibbs free energy (gives off energy)
what is an endergonic reaction?
reaction with a positive change in gibbs free energy (gains energy)
what is the difference between a homogenous and a hetergenous catalyst?
a homogenous catalyst is in the same state as the reactants, whereas a heterogenous catalyst is in a different state
What are four factors that can affect reaction rate?
- concentration of reactants
- temperature
- catalyst
- medium
when determining the rate law, how do I use data to find the orders of the reaction?
identify two trials where the concentration of only one reactant changes. any subsequent changes in rate can be attributed to that reactant.
change in rate = change in concentration ^ order
what are the only two ways to change the rate of a zero order reaction?
- temperature
2. catalyst
for a zero order reaction, what graph indicates the rate constant?
[reactant] vs. time
slope = -k
for a first order reaction, what graph indicates the rate constant?
ln[reactant] vs. time
slope = -k
for a second order reaction, what graph indicates the rate constant?
1/[reactant] vs time
slope = k
what is a broken-order reaction?
a reaction with a fractional rate order
what is a mixed-order reaction?
reaction that has rate order that changes over course of reaction
how do you find the order of a reaction?
add the exponents (ie. a second order reaction can have two reactants that are first order)
what does a first-order reaction indicate about reaction mechanism?
likely that reaction begins when a single reactant undergoes a chemical change itself without interacting with anything else
what does a second-order reaction indicate about reaction mechanism?
likely that reaction begins with the collision of two molecules
