Question

a
3. A hypothetical reaction, A, + B2 → 2 AB,
follows the mechanism as given below :
A2 = A +A
(Fast)
A + B,—— AB + B
(Slow)
A + B + AB
(Fast)
The overall order of reaction is​

Answer 1

Answer:

Since IT is the intermediate reactive species whose concentration is determined from equilibrium step.

Slow step is:

A + B  

2

​  

→AB+B (slow)

r = k[A][B  

2

​  

]

From equilibrium step

A  

2

​  

⇌A+A(fast)

k  

eq

​  

=  

[A  

2

​  

]

[A]  

2

 

​  

 

∴[A]=(k  

eq

​  

[A  

2

​  

]  

1/2

 

Substitute the value of [A] in equation (i),

r=k.k  

eq

​  

 

1/2

[A  

2

​  

]  

1/2

[B  

2

​  

]

Thus, order of reaction =  

2

1

​  

+1=1  

2

1

​