Question

For the reaction $ A{g_2}O(s) \to 2Ag(s) + \dfrac{1}{2}{O_2}(g) $ ; $ \Delta H,\Delta S,T $ are $ 40.63KJ/mol,108.8J/Kmol $ and $ 373.4K $ respectively, predict the feasibility of reaction.

Answer 1

Hint: Feasibility can be described as the reaction that happens spontaneously, which means no extra energy needs to be put in for the reaction. The feasibility of the reaction depends on the sign of the Gibbs free energy, if it is positive then the reaction is not feasible or if it is negative then the reaction is feasible.

Complete answer:
Gibbs free energy, denoted by $ G $, combines enthalpy and entropy into a single value. The change in free energy $ \Delta G $ , is equal to the sum of the enthalpy minus the product of the temperature and entropy of the system.
Spontaneous is a reaction that is considered to be natural because it is a reaction that occurs by itself without any external action towards it. Non spontaneous needs constant external energy applied to it in order for the process to continue and once we stop the external action the process will stop.
For the reaction, $ A{g_2}O(s) \to 2Ag(s) + \dfrac{1}{2}{O_2}(g) $
The value of, $ \Delta H = 40.63KJ/mol $
 $ \Delta S = 108.8J/Kmol $
 $ T = 373.4K $
The formula for Gibbs free energy is: $ \Delta G = \Delta H - T\Delta S $
 $ \Delta G = 40.63 - 373.4 \times 108.8 $
 $ \Delta G = - 40,585.29KJ $
Thus, the value of $ \Delta G < 0 $ , this means the value is negative, so we can say that the reaction is feasible.

Note:
 $ \Delta G $ depends only on the difference in free energy of products and reactants' final state or initial state. $ \Delta G $ Is independent of the path of the transformation and is unaffected by the mechanism of a reaction. If the reaction is in equilibrium the value of Gibb’s energy will be equal to zero. That means, there is no net change either in forward or reverse direction.