Question

Write the rate law for the reaction 2A + B → C if the reaction

(1) is second order in B and overall third order, –rA = ______

(2) is zero order in A and first order in B, –rA = ______

(3) is zero order in both A and B, –rA = ______

(4) is first order in A and overall zero order. –rA = ______

Answer 1

1.
`R=k[A]^1[B]^2`

2.
`R=k[B]^1`

3.
`R=k[A]^0[B]^0=k`

4.
`R=k[A]^1[B]^(-1)`

Step-by-step explanation:

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

(1) is second order in B and overall third order.

2A + B → C

Order of the reaction = sum of stoichiometric coefficient

= x + 2 = 3

x = 1

Rate of the reaction =R

`R=k[A]^1[B]^2`

(2) is zero order in A and first order in B.

2A + B → C

Rate of the reaction =R

`R=k[A]^0[B]^1=k[B]^1`

Order of the reaction = sum of stoichiometric coefficient

= 0 + 1 = 1

(3) is zero order in both A and B .

2A + B → C

Order of the reaction = sum of stoichiometric coefficient

= 0 + 0 = 0

Rate of the reaction =R

`R=k[A]^0[B]^0=k`

(4) is first order in A and overall zero order.

2A + B → C

Order of the reaction = sum of stoichiometric coefficient

= 1 + x = 0

x = -1

Rate of the reaction = R

`R=k[A]^1[B]^(-1)`