19. Chemical Thermodynamics

Entropy Calculations

Multiple Choice
What is the change in entropy of the surroundings (ΔSsurr) for the reaction of 2 SO2(g) + O2(g) → 2 SO3(g) at 25.0 °C, given that ΔH = -196 kJ?
Multiple Choice
For the following reaction at 27 °C, calculate ∆S°_rxn, ∆S_surr, and ∆S_tot. Determine if reaction is favorable.
Fe₂O₃ (s) + 3 H₂ (g) → 2 Fe (s) + 3 H₂O (g) ∆H_rxn = 98.8 kJ
Open Question
Find Δ_rS for the formation of CH₃Cl(g) from its elements in their standard states. standard thermodynamic quantities for selected substances at 25 °C.
Open Question
Calculate δs∘rxn for the following reaction. The δs∘ for each species is shown below the reaction. C₂H₂(g) + 2 H₂(g) → C₂H₆(g) s∘(J/mol⋅K) 200.9 130.7 229.2
Open Question
Calculate ∆S° for NH₃(g) + HCl(g) → NH₄Cl(s)
Open Question
Calculate ∆S° for C₃H₄(g) + 2 H₂(g) → C₃H₈(g).
Open Question
What is the S° of HgI₂(yellow) in J/mol-K?
Open Question
What is ∆G° for the reaction CaO(s) + CO₂(g) → CaCO₃(s)?
Open Question
What is the standard Gibbs free energy for the transformation of diamond to graphite at 298 K?
Multiple Choice
A reaction has ΔrH = -107 kJ mol^-1 and ΔrS = 285 J K^-1 mol^-1. At what temperature is the change in entropy for the reaction equal to the change in entropy for the surroundings?
Multiple Choice
Calculate ΔS°rxn for the reaction: 2NO(g) + O2(g) → 2NO2(g) given the standard molar entropies: S°(NO) = 210.7 J/mol·K, S°(O2) = 205.0 J/mol·K, S°(NO2) = 240.1 J/mol·K.
Multiple Choice
Calculate ∆S_rxn for the reaction 2NO(g) + O2(g) → 2NO2(g) given the following standard molar entropies: S°(NO) = 210 J/mol·K, S°(O2) = 205 J/mol·K, S°(NO2) = 240 J/mol·K.
Multiple Choice
For 1 mol of molecules randomly distributed among bulbs A, B, and C, use Boltzmann's formula to calculate the entropy of the state. If the number of microstates is 27, what is the entropy?
Multiple Choice
If the change in entropy of the surroundings for a process is -326 J/K at 439 K and constant pressure, what is the heat flow (ΔH) absorbed by the system?
Multiple Choice
The entropy change associated with the expansion of one mole of an ideal gas from an initial volume of V_i to a final volume of V_f at constant temperature is given by the equation, ΔS = R ln (V_f/V_i). If V_i = 2.0 L and V_f = 4.0 L, what is the entropy change associated with the expansion?