Short Answer TypeWhat do you understand by the ‘order of a reaction’? Identify the reaction order from each of the following units of reaction rate constant:
(i) L-1 mol-1
(ii) L mol-1 s-1
For the reaction
2NO(g) + Cl2(g) --> 2NOCl(g)
The following data were collected. All the measurements were taken at 263 K:
|
Experiment No. |
Initial [NO] (M) |
Initial [Cl2] (M) |
Initial rate of disappearance of Cl2(M/min) |
|
1 |
0.15 |
0.15 |
0.60 |
|
2 |
0.15 |
0.30 |
1.20 |
|
3 |
0.30 |
0.15 |
2.40 |
|
4 |
0.25 |
0.25 |
? |
(a) Write the expression for rate law.
(b) Calculate the value of rate constant and specify its units.
(c) What is the initial rate of disappearance of Cl2 in exp. 4?
Nitrogen pentoxide decomposes according to equation: 2N2O5(g)---> 4NO2(g) + O2(g)
This first order reaction was allowed to proceed at 40° C and the data below were collected:
|
[N2O5] (M) |
Time (min) |
|
0.400 |
0.00 |
|
0.289 |
20.0 |
|
0.209 |
40.0 |
|
0.151 |
60.0 |
|
0.109 |
80.0 |
(a) Calculate the rate constant. Include units with your answer.
(b) What will be the concentration of N2O5 after 100 minutes?
(c) Calculate the initial rate of reaction.
The rate constant of a first order reaction increases from 2 — 10-2 to 4 — 10-2when the temperature changes from 300 K to 310 K. Calculate the energy of activation (Ea).
(log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021)
(a) For a reaction A + B --> P, the rate law is given by,
r = k [A]1/2 [B]2.
What is the order of this reaction?
(b) A first order reaction is found to have a rate constant k = 5·5 x 10-14 s-1. Find the half-life of the reaction.
The rate of a reaction becomes four times when the temperature changes from 293 K to 313 K. Calculate the energy of activation (Ea) of the reaction assuming that it does not change with temperature.
[R = 8·314 J K-1 mol-1, log 4 = 0·6021]
A reaction is of second order with respect to a reactant. How is its rate affected if the concentration of the reactant is (i) doubled (ii) reduced to half?
The reaction N2(g) + O2(g) 2NO(g), contributes to air pollution whenever a fuel is burnt in air at a high temperature. At 1500 K, equilibrium constant K for it is 1.0 x 10-5. Suppose in a case [N2] = 0.80 mol L-1and [O2] = 0.20 mol L-1 before any reaction occurs. Calculate the equilibrium concentrations of the reactants and the product after the mixture has been heated to 1500 K.
For a reaction :
(i)Write the order and molecularity of this reaction.
(ii)Write the unit of k.
