1. Instantaneous rate =
dx
dt
, where dx is small change in conc. and dt
is the smallest interval of time.
2. Average rate =
x
t
∆
∆
, where
x
∆
is change in concentration and
t
∆
is
large interval of time.
3.
A + B
→
C + D
Rate of disappearance of −
=
d[A]
A
dt
, where d[A] is small change in
conc. of ‘A’ and dt is small interval of time
Rate of disappearance of B
d[B]
dt
−
=,
Rate of appearance of C
d[C]
dt
+
=
Rate of appearance of D
d[D]
dt
+
=
Rate
d[A] d[B] d[C] d[D]
dt dt dt dt
− −
= = = =
Unit of rate of reaction = mol L
-1
s-
1
4. Order of reaction:
x y
Remember: Order cannot be determined with a given balanced
chemical equation. It can be experimentally determined.
XII
Chemistry
CHAPTER 4 - CHEMICAL KINETICS
If rate law expression for a reaction is
Rate = k [A] [B]
Order of reaction = x + y
u
Important Terms, Definitions & Formulae
Formulae For CHEMICAL KINETICS
FORMULAS- C
HEMICAL KINETICS CHEAT SHEET
