1. Suppose a reaction is of the nth order and involves a single reactant of initial concentration
A0.
A  Product
Write the rate equation and deduce the expression for rate constant.
2. A substance decomposes at 600 K with a rate constant of 3.72x10-5 s-1. Calculate the half-life
of the reaction. What fraction will remain undecomposed if the substance is heated for 3
hours at 600 K?
3. The gas phase reaction between nitric oxide and oxygen is third order. The following rate
constants have been measured.
T/K
-9
6
-2 -1
Kx10 /cm mol s
80.0
143.0
228.0
300.0
413.0
564.0
41.8
20.2
10.1
7.1
4.0
2.8
The behavior is interpreted in terms of a temperature-dependent pre-exponential factor,
the rate equation being of the form:
k = A Tm exp(-E/RT)
where A and m are constants. Assume the activation energy to be zero and determine m to
the nearest half-integer.
4. The following table gives kinetic data for the following reaction at 25 C:
OCl¯ + I¯  OI¯ + Cl¯
[OCl¯]/mol L-1
[I¯]/ mol L-1
[OH¯]/mol L-1
D[OI¯]/dt
10-4 mol L-1 s-1
0.0017
0.0017
1.0
1.75
0.0034
0.0017
1.0
3.50
0.0017
0.0034
1.0
3.50
0.0017
0.0017
0.5
3.50
What is the rate law of the reaction? What is the value of the rate constant?
5. Given that the first-order rate constant for the overall decomposition of N2O5 is k = (4.3 x
1013 s-1)exp(-103000/RT), [The activation energy is in J mol-1] calculate
(a) The half-life at -10 ˚C
(b) The time required for 90 % reaction at 50 ˚C.
6. Derive the expression for the concentration of each species in the following elementary
reaction.
A + B  C (k1)
2A  D (k2)
Assume the initial concentrations of A and B to be A0 and B0 and that of C and D to be zero.