Question

The isomerization of methyl isonitrile, CH3NC, to acetonitrile, CH3CN, was studied in the gas phase at 215oC, and the following data were obtained: Time (s) [CH3NC] (M) 0 0.0165 2,000 0.0110 5,000 0.00591 8,000 0.00314 12,000 0.00137 15,000 0.00074 (a) Calculate the average rate of reaction, in M/s, for the time interval between each measurement.

Answer 1

Answer:

2.75 × 10⁻⁶ M/s

1.69 × 10⁻⁶ M/s

9.23 × 10⁻⁻⁷ M/s

4.43 × 10⁻⁻⁷ M/s

2.1 × 10⁻⁻⁷ M/s

Explanation:

We have the following information for the isomerization of methyl isonitrile

Time (s)      [CH₃NC] (M)

  0              0.0165

2000          0.0110

5000          0.00591

8000          0.00314

12000         0.00137

15000         0.00074

To calculate the average rate of reaction (r) for each interval, we need to use the following expression:

r = -Δ[CH₃NC]/Δt

Interval 0-2000 s

r = - (0.0110 M-0.0165 M)/2000 s - 0 s = 2.75 × 10⁻⁶ M/s

Interval 2000-5000 s

r = - (0.00591 M-0.0110 M)/5000 s - 2000 s = 1.69 × 10⁻⁶ M/s

Interval 5000-8000 s

r = - (0.00314 M-0.00591 M)/8000 s - 5000 s = 9.23 × 10⁻⁻⁷ M/s

Interval 8000-12000 s

r = - (0.00137 M - 0.00314 M)/12000 s - 8000 s = 4.43 × 10⁻⁻⁷ M/s

Interval 12000-15000 s

r = - (0.00074 M - 0.00137 M)/15000 s - 12000 s = 2.1 × 10⁻⁻⁷ M/s