The rate law for the reaction is: Rate = k [A] [B]3/2
Can the reaction be an elementary process?  Explain.
No. An elementary process would have a rate law with orders equal to its molecularities. Hence, they must be whole number.
Powdered sugar dissolves in water faster than crystalline sugar. Why?
Sugar in the powdered state has more surface area compared to the crystalline sugar. Due to this, powdered sugar dissolves fast.
Slow reactions requires high activation energy as compared to fast reactions. Do you agree with the statement?
This statement is correct. The rate of is inversely proportional to the activation energy. Clearly, slow reactions need more activation energy than the fast reactions.
A lump of coal burns at moderate rate in air while coal dust burns explosively. Explain.
In case of coal dust, greater surface area is available as compared to the solid coal. Clearly, coal dust will react faster than the lump of coal. Combustion is an exothermic reaction. Due to greater amount of heat evolved in the combustion of coal dust, it leads to explosion.
Why the reactions of high molecularity less in number?
The basic condition for the chemical reaction is the simultaneous collisions among the reacting species. As the number of reacting molecules taking part in a reaction increases, the chances of their simultaneous collisions go on decreasing. Thus, the reactions of high molecularity are rare.
In some reactions, the energy of colliding molecules is more than the threshold energy, yet the reaction is slow. Explain.
Although, the colliding molecules have sufficient energy needed for the reaction, yet they must be properly oriented as well. In case the reaction is slow, it means that the reactant molecules do not proper orientations.
Define order and molecularity of a reaction.
Order of reaction. It is the sum of the exponents to which the molar concentrations are raised while expressing the rate law of a reaction.
Molecularity. It is the number of the reactant species which collide simultaniously to bring about a chemical reaction.


Name the factors which influence the rate of reaction.
The factors which affect the rate of reaction are:
(i)Conc. of reactants (ii) Nature of reactants (iii) Temperature (iv) Catalyst (v) Surface area of the reactants.
On the basis of activation energy, how will you show slow and fast reactions.
If the activation energy is high, the reaction is slow. But the reaction is fast in case the activation energy is less.
State one condition under which a bimolecular reaction may be kinetically of first order reaction.
It is possible only if one of the reactant is taken in such a large excess that its concentration may hardly charge. Such a reactant will not contribute to the order. Thus, the bimolecular reaction will be of the first order. These are called pseudo unimolecular reactions.




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