Advertisements
Advertisements
प्रश्न
Why can we not determine the order of a reaction by taking into consideration the balanced chemical equation?
Advertisements
उत्तर
Balanced chemical equation often leads to incorrect order or rate law. For example the following reaction seems to be a tenth order reaction.
\[\ce{KClO3 + 6FeSO4 + 3H2SO4 -> KCl + 3H2O + 3Fe2 (SO4)3}\]
This is actually a second order reaction. Actually the reaction is complex and occurs in several steps. The order of such reaction is determined by the slowest step in the reaction mechanism. Order is determined experimentally and is confined to the dependence of observed rate of reaction on the concentration of reactants.
APPEARS IN
संबंधित प्रश्न
For a reaction: 
Rate = k
(i) Write the order and molecularity of this reaction.
(ii) Write the unit of k.
The following data were obtained during the first order thermal decomposition of SO2Cl2 at a constant volume :
SO2Cl2 (g) → SO2 (g) + Cl2 (g)
| Experiment | Time/s–1 | Total pressure/atm |
| 1 | 0 | 0.4 |
| 2 | 100 | 0.7 |
Calculate the rate constant.
(Given : log 4 = 0.6021, log 2 = 0.3010)
A reaction is first order in A and second order in B. Write the differential rate equation.
How does calcination differ from roasting?
Define the following term:
Pseudo first-order reaction
Define the following terms:
Half-life period of reaction (t1/2).
Rate law for the reaction \[\ce{A + 2B -> C}\] is found to be Rate = k [A][B]. Concentration of reactant ‘B’ is doubled, keeping the concentration of ‘A’ constant, the value of rate constant will be ______.
For a complex reaction:
(i) order of overall reaction is same as molecularity of the slowest step.
(ii) order of overall reaction is less than the molecularity of the slowest step.
(iii) order of overall reaction is greater than molecularity of the slowest step.
(iv) molecularity of the slowest step is never zero or non interger.
In a reaction if the concentration of reactant A is tripled, the rate of reaction becomes twenty seven times. What is the order of the reaction?
For a general reaction A → B, plot of concentration of A vs time is given in figure. Answer the following question on the basis of this graph.
(i) What is the order of the reaction?
(ii) What is the slope of the curve?
(iii) What are the units of rate constant?
Why does the rate of any reaction generally decreases during the course of the reaction?
For reaction 2A + B → BC + D which of the following does not Express the reaction rates
At concentration of 0.1 and 0.2 mol L–1 the rates of deem position of a compound were found to be 0.18 and 0.72 mol L–1 m–1. What is the order of the reaction?
The number of molecules of the reactants taking part in a single step of the reaction is indicative of ______.
For the reaction, \[\ce{A +2B → AB2}\], the order w.r.t. reactant A is 2 and w.r.t. reactant B. What will be change in rate of reaction if the concentration of A is doubled and B is halved?
The conversion of molecules A to B follow second order kinetics. If concentration of A is increased to three times, how will it affect the rate of formation of B?
Assertion (A): Order of reaction is applicable to elementary as well as complex reactions.
Reason (R): For a complex reaction, molecularity has no meaning.
