Reaction Rate
What does reaction rate measure?
change in concentration/time
If doubling [A] doubles rate, what is the order?
first order
Which plot is linear for a first-order reaction?
ln[A] vs time
Define half-life.
Time for concentration to halve
What units are typically used for reaction rate?
M/s
If doubling [A] quadruples rate, what is the order?
second order
Which plot is linear for a zero-order reaction?
[A] vs time
Which reaction type has constant half-life?
First-order reactions
What happens to reaction rate as reactant concentration decreases?
reaction slows
What is the overall order if Rate = k[A]²[B]?
Third order overall
Which plot is linear for a second-order reaction?
1/[A] vs time
If the half-life is 25 min, how long for two half-lives?
50 minutes
Define instantaneous rate.
rate at a specific time
What is the exponent in a rate law called?
Reaction order
What does the slope equal in a first-order plot?
−k
If 0.400 M becomes 0.200 M, how many half-lives passed?
one half-life
What mathematical concept represents instantaneous rate on a graph?
slope of tangent line
Can reaction order be determined from the balanced equation?
Must be determined experimentally
What does the intercept represent in a first-order integrated rate law plot?
The y-intercept = ln[A]₀, which is the natural log of the initial concentration.
Why do zero-order reactions not have constant half-life?
Because the rate is independent of the reactant concentration