<u>Answer:</u> The activation energy of the reverse reaction is 47 kJ/mol
<u>Explanation:</u>
The chemical equation for the decomposition of dinitrogen pentaoxide follows:

We are given:
Activation energy of the above reaction (forward reaction) = 102 kJ/mol
Enthalpy of the reaction = +55 kJ/mol
As, the enthalpy of the reaction is positive, the reaction is said to be endothermic in nature.
To calculate the activation energy for the reverse reaction, we use the equation:

where,
= Activation energy of the forward reaction = 102 kJ/mol
= Activation energy of the backward reaction = ?
= Enthalpy of the reaction = +55 kJ/mol
Putting values in above equation, we get:

Hence, the activation energy of the reverse reaction is 47 kJ/mol
Answer: 5.85kJ/Kmol.
Explanation:
The balanced equilibrium reaction is

The expression for equilibrium reaction will be,
![K_p=\frac{[p_{D}]\times [p_{C}]}^4{[p_{B}]^2\times [p_{A}]}](https://tex.z-dn.net/?f=K_p%3D%5Cfrac%7B%5Bp_%7BD%7D%5D%5Ctimes%20%5Bp_%7BC%7D%5D%7D%5E4%7B%5Bp_%7BB%7D%5D%5E2%5Ctimes%20%5Bp_%7BA%7D%5D%7D)
Now put all the given values in this expression, we get the concentration of methane.


Relation of standard change in Gibbs free energy and equilibrium constant is given by:

where,
R = universal gas constant = 8.314 J/K/mole
T = temperature = 
= equilibrium constant = 10.6



Thus standard change in Gibbs free energy of this reaction is 5.85kJ/Kmol.
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Decantation
Centrifugation
Filtration
Evaporation