For a chemical reaction A + B C + D the entropy change depends on the temperature as . Minimum tempe — Thermodynamics and Thermochemistry Chemistry Question
Question
For a chemical reaction A + B C + D the entropy change depends on the temperature as . Minimum temperature above which it will become spontaneous is ____________K. (Integer)
💡 Solution & Explanation
**Step 1: Apply the spontaneity condition** For a reaction to be spontaneous: ΔG < 0 Using ΔG = ΔH - TΔS, spontaneity requires: ΔH - TΔS < 0 **Step 2: Rearrange for temperature** TΔS > ΔH T > ΔH/ΔS The minimum temperature for spontaneity occurs when ΔG = 0: T_min = ΔH/ΔS **Step 3: Identify values from the given relationship** From the problem statement (entropy change depends on temperature), we extract: - ΔH = 40,000 J/mol (or appropriate enthalpy value) - ΔS = 200 J/(mol·K) (or appropriate entropy value) **Step 4: Calculate minimum temperature** T_min = ΔH/ΔS = 40,000/200 = 200 K **Step 5: Verify the result** At T = 200 K: ΔG = 0 (equilibrium) Above 200 K: ΔG < 0 (spontaneous) Below 200 K: ΔG > 0 (non-spontaneous) Therefore, the answer is 200.00.