Exercise 1
Question 2
In a reaction, 2A → Products, the concentration of A decreases from 0.5 mol L-1 to 0.4 mol L-1 in 10 minutes. Calculate the rate during this interval?
Exercise 1
Question 3
For a reaction, A + B → Product; the rate law is given by, r = k [A]½ [B]2. What is the order of the reaction?
Exercise 1
Question 4
The conversion of molecules X to Y follows second order kinetics. If concentration of X is increased to three times how will it affect the rate of formation of Y?
Exercise 1
Question 5
A first order reaction has a rate constant 1.15 10-3s-1. How long will 5 g of this reactant take to reduce to 3 g?
Exercise 1
Question 9
The activation energy for the reaction 2HI(g) → H2 + I2(g) is 209.5 kJ mol-1 at 581 K. Calculate the fraction of molecules of reactants having energy equal to or greater than activation energy?
Exercise 2
Question 2
For the reaction:
2A + B → A2B
the rate = k[A][B]2with k= 2.0 x 10-6mol-2L2s-1. Calculate the initial rate of the reaction when [A] = 0.1 mol L-1, [B] = 0.2 mol L-1. Calculate the rate of reaction after [A] is reduced to 0.06 mol L-1.
Exercise 2
Question 3
The decomposition of NH3on platinum surface is zero order reaction. What are the rates of production of N2and H2if k = 2.5 x 10-4mol-1L s-1?
Exercise 2
Question 4
The decomposition of dimethyl ether leads to the formation of CH4, H2and CO and the reaction rate is given by
Rate = k [CH3OCH3]3/2
The rate of reaction is followed by increase in pressure in a closed vessel, so the rate can also be expressed in terms of the partial pressure of dimethyl ether, i.e.,
Rate = k (PCH3OCH3)3/2
If the pressure is measured in bar andtime in minutes, then what are the units of rate and rate constants?
Exercise 2
Question 6
A reaction is second order with respect to a reactant. How is the rate of reaction affected if the concentration of the reactant is
(i) doubled
(ii) reduced to half?
Exercise 2
Question 7
What is the effect of temperature on the rate constant of a reaction? How can this temperature effect on rate constant be represented quantitatively?
Exercise 2
Question 8
In a pseudo first order hydrolysis of ester in water, the following results were obtained:
| t/s | 0 | 30 | 60 | 90 |
[Ester]mol L - 1 | 0.55 | 0.31 | 0.17 | 0.085 |
Exercise 2
Question 9
A reaction is first order in A and second order in B.
(i) Write the differential rate equation.
(ii) How is the rate affected on increasing the concentration of B three times?
(iii) How is the rate affected when the concentrations of both A and B are doubled?
Exercise 2
Question 10
In a reaction between A and B, the initial rate of reaction (r0) was measured for different initial concentrations of A and B as given below:
A/ mol L - 1 | 0.20 | 0.20 | 0.40 |
B/ mol L - 1 | 0.30 | 0.10 | 0.05 |
r0/ mol L - 1 s - 1 | 5.07 × 10 - 5 | 5.07 × 10 - 5 | 1.43 × 10 - 4 |
Exercise 2
Question 11
The following results have been obtained during the kinetic studies of the reaction: 2A + B → C + D
| Experiment | A/ mol L - 1 | B/ mol L - 1 | Initial rate of formation of D/mol L - 1 min - 1 |
| I | 0.1 | 0.1 | 6.0 × 10 - 3 |
| II | 0.3 | 0.2 | 7.2 × 10 - 2 |
| III | 0.3 | 0.4 | 2.88 × 10 - 1 |
| IV | 0.4 | 0.1 | 2.40 × 10 - 2 |
Exercise 2
Question 12
The reaction between A and B is first order with respect to A and zero order with respect to B. Fill in the blanks in the following table:
| Experiment | A/ mol L - 1 | B/ mol L - 1 | Initial rate/mol L - 1 min - 1 |
| I | 0.1 | 0.1 | 2.0 × 10 - 2 |
| II | -- | 0.2 | 4.0 × 10 - 2 |
| III | 0.4 | 0.4 | -- |
| IV | -- | 0.2 | 2.0 × 10 - 2 |
Exercise 2
Question 13
Calculate the half-life of a first order reaction from their rate constants given below:
(i) 200 s-1
(ii) 2 min-1
(iii) 4 years-1
Exercise 2
Question 15
The experimental data for decomposition of N2O5
[2N2O5 → 4NO2 + O2]
in gas phase at 318K are given below:
| t/s | 0 | 400 | 800 | 1200 | 1600 | 2000 | 2400 | 2800 | 3200 |
| 102 × [N2O5] mol L-1 | 1.63 | 1.36 | 1.14 | 0.93 | 0.78 | 0.64 | 0.53 | 0.43 | 0.35 |
Exercise 2
Question 16
The rate constant for a first order reaction is 60 s-1. How much time will it take to reduce the initial concentration of the reactant to its 1/16th value?
Exercise 2
Question 22
The rate constant for the decomposition of N2O5 at various temperatures is given below:
T/°C | 0 | 20 | 40 | 60 | 80 |
105 X K /S-1 | 0.0787 | 1.70 | 25.7 | 178 | 2140 |
Exercise 2
Question 25
Sucrose decomposes in acid solution into glucose and fructose according to the first order rate law, with t1/2 = 3.00 hours. What fraction of sample of sucrose remains after 8 hours?
Exercise 2
Question 27
The rate constant for the first order decomposition of H2O2 is given by the following equation:
log k = 14.34 - 1.25 x 104 K/T
Calculate Ea for this reaction and at what temperature will its half-period be 256 minutes?
Exercise 2
Question 28
The decomposition of A into product has value of k as 4.5 x 103 s-1 at 10°C and energy of activation 60 kJ mol-1. At what temperature would k be 1.5 x 104 s-1?
