AP Chemistry / Unit 5: Kinetics
5.2 Introduction to Rate Law
Notes
$$\text{rate}=k[A]^m[B]^n$$
- Orders ($m$, $n$) come from experiments, not the balanced equation.
- Doubling $[A]$: rate doubles (1st order), quadruples (2nd), unchanged (0th).
Practice
Doubling $[A]$ quadruples the rate. The order in $A$:
$2^2=4$.
Rate $=k[A][B]^2$. The overall order:
$1+2$.
Doubling $[B]$ doesn't change the rate. The order in $B$:
$2^0=1$.
Ready for more? Take the Unit 5 test.