## Order of reaction-

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## Order of reaction-

### Reaction,

A + B ———>AB

Rate       [A][B]

Rate = K[A][B]

mole dm -3/min = K [mole dm-3]2

unit of K = mole dm-3 /min (mole dm-3)2

#### unit of K = dm3 mole-1 min-1 Ans.

ii) For zero order reaction,

Rate = K

dx/dt = K

unit of K =( mole / litre)/sec

### Rate = K[A]n

mole litre-1/sec. = K [mole litre-1]n

unit of K = [mole litre-1sec-1] / [mole litre-1]n

unit of K =  [mole litre-1](1-n )sec-1

i) If n=1/2, then

unit of K =  [mole litre-1](1-n)sec-1

unit of K =  [mole litre-1](1-1/2) sec-1

#### unit of K =  [mole litre--1]1/2 sec-1 Ans.

ii) If n=3/2, then

unit of K =  [mole litre-1](1 -n)sec-1

unit of K =  [mole litre-1](1- 3/2) sec-1

#### unit of K =  [mole litre-1]-1/2sec-1 Ans.

iii) If n=3 , then

unit of K =  [mole litre-1](1 -n)sec-1

unit of K =  [mole litre-1](1 -3) sec-1 =  [mole litre-1]-2 sec-1

### Solution )

#### Overall order = 1 +2= 3 Ans.

Rate = K [H2][NO]2

unit of K = rate / [H2][NO]2

unit of K = [mole litre-1sec-1] / [mole litre-1]3

#### unit of K = [mole litre-1]2 sec-1 = mole 2 litre -2 sec-1 Ans.

ii)  Rate = K [H2O2][I]

#### Overall order = 1 +1= 2 Ans.

Rate = K [H2O2][I]

unit of K = rate / [H2O2][I]

unit of K = [mole litre-1sec-1] / [mole litre-1]2

#### unit of K = [mole litre-1 ]sec-1 = mole -1 litre  sec-1 Ans.

iii)

Rate = K [CH3CHO]3/2

#### Overall order = 3/ 2 Ans.

Rate = K [CH3CHO]3/2

unit of K = rate / [CH3CHO]3/2

unit of K = [mole litre-1sec-1] / [mole litre-1]3/2

iv)

Rate = K [NOBr]2

#### Overall order =  2 Ans.

Rate = K [NOBr]2

unit of K = rate /[NOBr]2

unit of K = [mole litre-1sec-1] / [mole litre-1]2

v)

Rate = K [NO]2

#### Overall order =  2 Ans.

Rate = K [NO]2

unit of K = rate /[NO]2

unit of K = [mole litre-1sec-1] / [mole litre-1]2