(i) Graphical Method:-
2 N2O5  4 NO2 + O2
Illustration:- 2 N2O5 4 NO2(I) + O2
Find (1) rate law (2) Rate constant (3) order of rxn.
Ans:- Rate = 
K = 
(2) Initial Rate method:-
Illustration:- 2A + B C + D
What is (1) rate law, (2) order w.r.t. each reactant & overall order (3) Rate constant
Ans:- Let Rate = K
Dividing (2) by (1)
order w.r.t.  is 2
Dividing (4) by (3)
Order w.r.t. A = 1
Overall order = Order of A + order of B = 1 + 2 = 3
Rate law = K[A] [B]2
6 X 10-3 = K[0.1] [0.1]2
K = 6 mol-2L2min-1
(3) Itegrated Rate law:-
D.S assed earlier
(4) Halhe life method:-
Question:-
to be 25 min. Calculate order of rxn.
Ans:- 
1 - n = 1 => n = 0 ie zero order.
Ostwald Isolation method:- In this method, for rxn.
aA + bB + cC Products
if oredr w.r.t. A, B & C are  respectively, then rate law
Rate = K
If B & C are in large excess. their cons. remains almost constant.
Rate = 
Thus order w.r.t. A is found one.
Similarly order w.r.t. B & C can be determined.
Illustrution :- rxn. CH3COF + H2O CH3COOH + HF studied in two different experements. In Ist exp., starting initially with [CH3COF] = 0.01 M & [H2O] = 1M, conc. of CH3COF at different times was found.
In IIndf Exp. ; [CH3COF] = 0.8 M & [H2O] = 0.02 M
As rate is changing with time. or these are not const decrease in cons. permit time. So, nan not be zero oredr.
Let test for Ist oredr
Since K comes out to be constant, order w.r.t. to CH3COF = 1
In Exp. II, [CH3COF] >> [H2O]
Let us test for Ist order
Since K comes out to be constant, order of rxn. w.r.t. H2O is 1.
Examples of Ist Order rxn.:-
(1) Decomposition of N2O5
Volume of oxygen gas collected at any time(vt) }  Amt. of N2O5 decomposed (x)
ie x Vt
Volume of gas collected at infinete time (V) } Amt. of N2O5 initially taken (a)
Substituting these value in Ist order eq.
We get, 
Illustration:-
Caculate rate Constant
Ans:- 
] 
Rate constant is mostly constant.
Avg. Value = 0.01981.min-1
(2)Decomposition of H2O2:-
H2O2 solution can be titrated against KMnO4 solution.
Vol. of KMnO4 sol. used at zero time (V0) } align=center /> Initial cons. of H2O2 (a)
ie a V0 Vol. of KMnO4 sol. used at any instant of time t (Vt) } amt. of H2O2 Present at that instant i.e. (a - x)
i.e. (a - x) Vt
Illustration:
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