The decomposition of nitrous oxide at 565 °C

N2O(g) --> N2(g) + ½ O2(g)

is second order in N2O with a rate constant of 1.10×10-3 M-1 s-1. If the initial concentration of N2O is 1.42 M, the concentration of N2O will be M after 2.18×103 seconds have passed.

b) The gas phase decomposition of hydrogen peroxide at 400 °C
H2O2(g) --> H2O(g) + ½ O2(g)
is second order in H2O2.
In one experiment, when the initial concentration of H2O2 was 4.18×10-2 M, the concentration of H2O2 dropped to 9.57×10-3 M after 81.5seconds had passed.
Based on these data, the rate constant for the reaction is ? M-1 s-1.

c) The rearrangement of cyclopropane to propene at 500 °C

(CH2)3 --> CH3CH=CH2

is first order in (CH2)3 with a rate constant of 6.70×10-4 s-1.

1) If the initial concentration of (CH2)3 is 0.142 M, the concentration of (CH2)3 will be ? M after 2213 s have passed.

2) If the initial concentration of (CH2)3 is 0.202 M, the concentration of (CH2)3 will be 3.78×10-2 M after ? s have passed.