Question

In a study conducted at the same temperature, the following data for reaction producing nitrosyl bromide were collected.

Trial	Initial [NO] (M)	Initial [Br2] (M)	Initial rate (M/s)
1	0.150	0.240	46
2	0.300	0.240	185
3	0.300	0.480	369

Part C

What is the rate of the reaction when the initial concentration of NO is 0.400 M and that of Br2 is 0.245 M ?

Express your answer to three significant figures and include the appropriate units.

Answer 1

let Rate (-rA)= K[NO]^m [ Br2^]n

m and n are orders with respect to [NO] and [Br2]

from trial -1   46= K [ 0.15]^m [ 0.24]ⁿ (1) and from trial-2 185= K[ 0.3]^m [0.24^]n    (2)

Eq.2/ Eq.1 gives (2)^m= (185/46) =4.02

m= 2   from trial 3   369= K[ 0.3]^m [ 0.48]ⁿ      (3)

Eq.3/Eq.2 = 369/185= 2ⁿ,   n=1

the reation rate becomes -rA= K[NO]² [Br2] from trail 1 46= K[ 0.15]² [0.24]

K = 8519 /M².S

the rate becomes - rA= 8519 [NO]² [Br2]1

fro [NO] =0.4M and[Br2] =0.245 rate= 8519*[0.4]2 [0.245]=333.95 M/s