Question

At elevated temperatures, in the absense of a catalyst, nitrous
oxide decomposes by a first order proces according the the
equation: 2N_{2}O (g) --> 2N_{2} (g) +
O_{2} (g). From an experiment at 430 degrees Celsius,
*k* is found to be 3.8 x 10^{-5} s^{-1}; at
700 degrees Celsius, *k* is found to be 1.0
s^{-1}.

a. Using the two-point version of the linearized Arrhenius
equation, please find the activation energy (kJ/mol) for the
decomposition of N_{2}O (g).

b. Given that the decomposition is first order, please write the rate law.

c. Using your rate law information, please write a mechanism
that proceeds in three elementary steps, with the first being
rate-determining, the third step being the fastest, and the
intermediate N_{2}O_{2} being formed in the second
step. Please write the rate law next to each step. Please write the
overall reaction underneath the three steps and make sure it all
"adds up."

d. On a grid, to scale, please sketch the potential energy vs.
reaction progress profile for the first order decompositon of
N_{2}O (g). Please clearly label the graph axes, the
reactants and products, *E _{a}*, and
Δ

Answer #1

From Arhenius equation, ln K= lnKo-Ea/RT

Where K =Rate constant, Ko= Frequency factor, T= Temperature in K, R= 8.314 J/mole.K, Ea= activation energy.

At two different temperatures, the equation can be written as

Ln(K2/K1)= (Ea/R)*(1/T1-1/T2)

K2= 1/s and K1= 3.8*10-5/s, T1= 430deg.c= 430+273=703K, T2= 700+273=973K

Ln(1/3.8*10-5)= (Ea/R)*(1/703-1/973)

Ea= 214375 J/mole=214.375 KJ/mole

b) The rate law (r) is = K[N2O]

c) N2O--->N2+1/2O2 ( step-1), slowest step( rate determining step)

N2O+1/2O2<-<àN2O2 ( step-2),

N2O2------> N2+O2 fast and equilibrium

d)

Nitrous oxide (N2O) decomposes at 600°C according to the
balanced equation
2N2O(g) → 2N2(g) + O2(g)
A reaction mechanism involving three steps is shown below.
Identify all of the catalysts in the following mechanism.
Cl2(g) → 2Cl(g)
N2O(g) + Cl(g) → N2(g) + ClO(g) (occurs twice)
ClO(g) + ClO(g) → Cl2(g) + O2(g)

A suggested mechanism for the gas phase decomposition of nitrous
oxide is:
step 1 slow: N2O
--> N2 + O
step 2 fast: N2O + O
--> N2 + O2
(1) What is the equation for the overall
reaction? Use the smallest integer coefficients possible.
(2) Which species acts as a catalyst? Enter
formula.
(3) Which species acts as a reaction
intermediate? Enter formula.
(4) Complete the rate law for
the overall reaction that is consistent with this mechanism.
(Use...

Please study the table of data below, collected for the gas
phase combination reaction of N2O with O3 at 298 K and constant
volume (1.00 L).
Experiment
[N2O]0
[O3]0
Initial rate of reaction of O3
(M/s)
1
.010
.010
6.01 x 10^-4
2
.010
.020
1.20 x 10^-3
3
.020
.020
1.19 x 10^-3
A) Please determine the order of each reactant and write the rate
law for the overall reaction.
B) The overall reaction is: N2O (g) + O3...

Laughing Gas Nitrous oxide (N2O) is used as
an anesthetic (laughing gas) and in aerosol cans to
produce whipped cream. It is a potent greenhouse gas and
decomposes slowly to N2 and O2:
2 N2O(g) → 2 N2(g) +
O2(g)
a. If the plot of ln[N2O] as a function
of time is linear, what is the rate law for the reaction?
b. How many half-lives will it take for the
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concentration?...

The decomposition of ethylene oxide (CH2)2O (g), at 652K is a
first order reaction with a rate constant of k=0.0012 min^-1 and an
activation energy of 218 KJ/mol.
(CH2)2O (g) ----> CH4 (g) + CO (g)
Calculate: a) The rate constant of the reaction at 525K. and b)
the temperature at which the rate constant is k=0.01 min^-1
Thank You

The decomposition of HI (g) into its elements in the gas phase
at 800 K is found to proceed by a second order process.
A) Please write a balanced equation for the reaction (smallest
integer ratio of coefficients, please).
B) Please write the rate law for the reaction:
C) Given that it takes 142 s for the [HI (g)] to change from 6.75 x
10-2 M to 3.50 x 10-2 M, please calculate the value of the rate
constant (and...

H2O2 decomposes at 20˚C in a first order
reaction where k = 1.06 x 10-3min-1. If the
initial concentration of H2O2 is 0.020 M,
what is [H2O2] after 3.5 days?
a.
9.6x10-5 M
b.
5.1x10-5 M
c.
4.4x10-5 M
d.
1.7x10-5 M
For the following
reaction, calculate the average reaction rate over the
last 2 minutes using the table of data below.
H2(g) +
2ICl(g)
I2(g) + 2HCl(g)
Time
(min) [ICl] (M)
-------------- -----------
0
2.000
2 ...

1)A second order reaction has a rate constant of 3.7
M-1min-1. if the initial concentration of the reactant is 0.0100M,
what is the concentration remaining after 15 min?
a) .0099M
b) .0056M
c) .0025M
d) .0064M
2) the rate constant for the first order decomposition
of A at 500 degrees Celsius is 9.2 x 10 to the negative 3rd powers
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decompose
a) 2.5 x...

The overall order of an elementary step directly corresponds to
its molecularity. Both steps in this example are second order
because they are each bimolecular. Furthermore, the rate law can be
determined directly from the number of each type of molecule in an
elementary step. For example, the rate law for step 1 is
rate=k[NO2]2
The exponent "2" is used because the reaction involves two NO2
molecules. The rate law for step 2 is
rate=k[NO3]1[CO]1=k[NO3][CO]
because the reaction involves only...

The decomposition of N2O5 is first order reaction. N2O5(g)
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constant for the reaction is 1.2x10^-5 s^-1. Calculate the partial
pressure of NO2(g) produced from 1.0L of 0.700M N2O5 solution at 48
degC over a period of 22 hours if the gas is collected in a 10.0L
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