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After the reactio is over between adsorb...

After the reactio is over between adsorbed reactants, it is important to create space for the other reactant molecules to approach the surface and react. The process responsible for this is known as

A

sorption

B

desorption

C

physisorption

D

chemisorption

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The correct Answer is:
B
Desorption removes products from the surface to create space for the reactants.
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Which of the following factors are responsible for the increase in the rate of a surface catalysed reaction? (i) A catalyst provides proper orientation for the reactant molecules to react. (ii) heat of adsorption of reactants on a catalyst helps reactant molecules to overcome activation energy. (iii) The catalyst increases the activation energy of the reactio.

Which of the following factors are responsible for the increase in the rate of a surface catalysed reaction ? (I) A catalyst provides proper orientation for the reactant molecules (II) Heat of adsorption of reactants on a catalyst helps reactant molecules to overcome activation energy (III) The catalyst increases the activation energy of the reaction (IV) Adsorption increases the local concentration of reactant molecules on the surface of the catalyst. Select the correct answer using the codes given below:

Many a time the reaction are carried out when the reactants are not present in the amounts required by a balanced chemical reaction. In such situations, one reactant is in excess over other. The reactant which is present in th lesser amount gets conserved after sometime and after that no further reaction takes place whatever be the amount of other reactant is present .Hence, the reactant which gets consumed , limits the amount of products formed and is therefore called limiting reagent. To determine the limiting reagent find the value of phi which is the ratio of (given) mole of a substance to the stoichiometric coefficient of that substance . The limiting reagent is the reagent which has minimum value of phi . In the above question , how much reactant is remaining at the completion of reaction and which one?

The activity of a catalyst has been explained in terms of spontaneous adsorption of reactant moleculse on the surface of catlyst and ther by forming an activated adsorbed complex along with evolution of heat . The adorbed activated complex undergoes to decompositio to regencerate catlyst and give products . adorpton is of two types : (i) Physical adsorptio due to van der Waal's forces of attraction between reactant and catalyst molecules , weak , less exothermic, mulitlay and non-dirctional . (ii) Chemical dasorpton due to free valencies , strong, more exothermic, unilayer. The extent of adormpotion ( x//m) vs temperature at constant pressure gives isobars. Freundilish studied influence of pressure on the phusical adorptons and reported that log x/m log K + 1/n log P . During adorption of reactant momecules on catalyst surface :

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