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### What is the concept of activation energy?

Concept of activation energy: The minimum extra amount of energy absorbed by the reactant molecules so that their energy becomes equal to threshold value is called activation energy. In other words, activation energy is the difference between the threshold energy and the average energy of the ...

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### What is the relationship between the rate of reaction and collision frequency?

Relationship between the rate of reaction and collision frequency: If Z is the collision frequency and f is the fraction of molecules whose collisions are effective, then evidently: Rate of reaction = - dx / dt = Z x f …………………………….. (1) Further according to kinetic theory of ...

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### Explain the collision theory.

Collision theory: According to collision theory, a reaction takes place because the molecules collide with each other. The number of collisions that take place per second per unit volume of the reaction mixture is called collision frequency. At ordinary temperature and pressure, the value of collision frequency ...

### What do you mean by pseudo unimolecular reactions?

Pseudo unimolecular reactions: Consider the following acid catalysed reactions: 1. Hydrolysis of ethyl acetate: CH3COOC2H5 + H2O + H+ ----------->CH3COOH + C2H5OH 2. Inversion of cane sugar: C12H22O11 + H2O + H+ ---------------> C6H12O6 + C6H12O6 Both the above reactions are bimolecular but are found to be of first order, as experimentally it ...

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### A first order reaction is 40% complete in 50 minutes. Calculate the value of the rate constant. In what time the reaction will be 80% complete?

1) For the first order reaction: k = (2.303 / t) log (a / a – x) When x = (40 / 100) a = 0.4 a t = 50 minutes (given) Therefore, k = (2.303 / 50) log (a / a – 0.4 a) k = (2.303 / 50) log ...

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### Discuss the experimental methods for determination of rate constant.

Experimental methods for determination of rate constant are discussed below: 1. Concentration change method: In this method the concentration of one of the reactants or products is measured at different times. 2. Volumetric method: In this method the volume of some gaseous product is noted at different times. E.g. In the ...

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### What will be the amount of the substance left after n half-lives? The half life period of a first order reaction is 60 minutes. What percentage will be left after 240 minutes?

Amount of the substance left after one half life = A0 / 2 Amount of the substance left after two half lives = A0 / 22 Amount of the substance left after three half lives = A0 / 23 In general, Amount of the substance left after n half ...

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### Calculate the order of reaction from two different half values.

Consider the two different initial concentrations and finding their half lives, the order of reaction (n) can be calculated as follows: Taking log on both sides we will get: log (t1/2) 1 - log (t1/2) 2 = n – 1 (log [A0] 2 - log [A0] 1)

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