Question

For the exothermic reaction $$A + B \to C + D,\Delta H$$     is the heat of reaction and $${E_a}$$ is the energy of activation. The energy of activation for the formation of $$A + B$$  will be

A. $${E_a}$$
B. $$\Delta H$$
C. $${E_a} + \Delta H$$  
D. $$\Delta H - {E_a}$$
Answer :   $${E_a} + \Delta H$$
Solution :
For the exothermic reaction the energy of products is always less than the reactants. If $${E_a}$$ is the energy of activation for the forward reaction, the energy of activation for backward reaction is $${E_a} + \Delta H$$

Releted MCQ Question on
Physical Chemistry >> Chemical Kinetics

Releted Question 1

If uranium (mass number 238 and atomic number 92) emits an $$\alpha $$ -particle, the product has mass no. and atomic no.

A. 236 and 92
B. 234 and 90
C. 238 and 90
D. 236 and 90
Releted Question 2

The rate constant of a reaction depends on

A. temperature
B. initial concentration of the reactants
C. time of reaction
D. extent of reaction
Releted Question 3

The specific rate constant of a first order reaction depends on the

A. concentration of the reactant
B. concentration of the product
C. time
D. temperature
Releted Question 4

A catalyst is a substance which

A. increases the equilibrium concentration of the product
B. changes the equilibrium constant of the reaction
C. shortens the time to reach equilibrium
D. supplies energy to the reaction

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Chemical Kinetics


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