Answer :
Final answer:
The standard molar entropy change for dissolving KNO₃ in water is 114.8 J/(mol ·K).
Explanation:
The standard molar entropy change for dissolving KNO₃ in water can be calculated by subtracting the sum of the standard molar entropies of the reactants from the sum of the standard molar entropies of the products. In this case, the reactants are solid KNO₃ and water, and the products are aqueous K+ and NO₃⁻ ions. Therefore, the standard molar entropy change (ΔS°) can be calculated as follows:
ΔS° = (Entropy of K+(aq) + Entropy of NO₃⁻(aq)) - (Entropy of KNO₃)
= (101.2 J/(mol ·K) + 146.70 J/(mol ·K)) - 133.1 J/(mol ·K)
= 247.9 J/(mol ·K) - 133.1 J/(mol ·K)
= 114.8 J/(mol ·K)
