AP Chemical Thermodynamics Flashcards

Chemical Thermodynamics Concepts

• The reaction of sulfur dioxide (SO2) with oxygen (O2) produces sulfur trioxide (SO3).
• Absolute entropies (S°) of O2(g) and SO3(g) are necessary for thermodynamic calculations.
• To find the standard entropy of SO2(g), the formula is:
  • S° = 1/2 [187 + (2 × 257) - 205] J/(mol⋅K).
• The relationship used is derived from the equation ΔS°reaction = Σ(moles of substance × S°)products - Σ(moles of substance × S°)reactants.

Equilibrium and Thermodynamic Favorability

• The synthesis of ammonia (NH3) can be analyzed through the equilibrium constant (K) and standard enthalpy change (ΔH°rxn).
• A reaction is thermodynamically favorable at 298 K and constant pressure if the Gibbs free energy change (ΔG°) is less than zero.
• The equation ΔG° = -RT ln K can be applied; a negative ΔG° indicates a favorable process.
• If ln K is positive, ΔG° becomes negative, affirming thermodynamic favorability (ΔG° > 0).

This quiz consists of flashcards covering the principles of chemical thermodynamics, specifically focusing on entropy calculations in reactions. You'll explore the relationship between entropies of reactants and products and practice your problem-solving skills. Whether you're preparing for the AP exam or just refreshing your knowledge, these flashcards will be a valuable resource.