Answer:
To calculate the standard change in entropy for the reaction, we need to consider the difference in entropy between the products and the reactants.
The balanced equation for the reaction is:
2NH3(g) + 2O2(g) → N2O(g) + 3H2O(g)
The standard change in entropy (ΔS°) can be calculated using the formula:
ΔS° = ΣS°(products) - ΣS°(reactants)
Where ΣS° represents the sum of the standard molar entropies of the species involved.
Looking up the standard molar entropies (S°) for each species involved in a reliable source, we find:
S°(NH3) = 192.77 J/(mol·K)
S°(O2) = 205.15 J/(mol·K)
S°(N2O) = 219.62 J/(mol·K)
S°(H2O) = 188.72 J/(mol·K)
Now we can calculate the standard change in entropy:
ΔS° = [ΣS°(products)] - [ΣS°(reactants)]
= [S°(N2O) + 3S°(H2O)] - [2S°(NH3) + 2S°(O2)]
= [219.62 J/(mol·K) + 3 * 188.72 J/(mol·K)] - [2 * 192.77 J/(mol·K) + 2 * 205.15 J/(mol·K)]
= 811.2 J/K
Therefore, the standard change in entropy for the reaction is 811.2 J/K.