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