Nitrogen dioxide undergoes thermal decomposition according to the second-order reaction 2 NO2(g) → 2 NO(g) + O2(g). When 0.700 M NO2 is allowed to react for 90.0 seconds, its concentration falls to 0.0463 M. What is the rate constant for the reaction?

K = 0.2241 M-1 s-1

Explanation:

∴ a: NO2

∴ α = 2 second order

⇒ - δCa/δt = K Ca²

⇒ - ∫δCa/Ca² = K*∫δt

⇒ [ 1/Ca - 1/Cao ] = K*t

∴ Ca = 0.0463 M

∴ Cao = 0.700 M

∴ t = 90.0 s

rate constant (K):

⇒ - [ 1/0.0463 - 1/0.700 ] = K*(90.0 s)

⇒ 20.1697 M-1 = K*(90.0 s)

⇒ K = 0.2241 M-1 s-1

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

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