University:
The Pennsylvania State University
Course:
CHEM 450 | Thermodynamics
Academic year:

2024
Views:

284

Pages:

2
Author:

Alexis H.

Problem Set #22 Assigned: February 23, 2024 Due: Feb. 26, 2024 at 2:30 pm 1. Describe the meaning and applicability of the following two expressions: (a) dAT,V < 0 (b) dGT,p < 0 Please center your discussion around the following equations: Ssys + Ssurr = Stot and 0 < Stot. 2. Explain the meaning of processes associated with: (a) dAT,V = 0 (b) dGT,p = 0 (c) dAT,V > 0 (d) dGT,p > 0. 3. Under what circumstances and why can the spontaneity of a process be discussed in terms of the properties of the system alone? 4. (a) Are the Gibbs function, G, and Helmholtz function, A, state functions? (b) Do G and A have intensive or extensive properties? 5. (a) Consider a process which occurs for which U = -7.1 kJ and S = -27 J/K. Over what range of temperatures can usable work be obtained? (b) Consider a process which occurs for which U = 7.1 kJ and S = 27 J/K. Over what range of temperatures can usable work be obtained? 1. (a) This means that at constant temperature and pressure the total entropy would be less than zero meaning that it is a spontaneous process (b) This means that at constant temperature and pressure the total entropy, of the system and surroundings combined, is less than zero making it a spontaneous process 2. (a) represents a system in equilibrium while having constant temperature and volume, meaning the same entropy of the system is equal and opposite the the entropy of the surroundings (b) represents a system in equilibrium using the gibbs free energy equation, at constant temperature and pressure, meaning the entropy of the system is equal and opposite to the entropy of the surroundings (c) represents a non-spontaneous reaction at constant temperature and volume (d) represents a non-spontaneous reaction at constant temperature and pressure for gibbs free energy 3. spontaneity occurs when delta G is negative, delta H is negative, and delta S is positive. Spontaneity can be discussed in the terms of the properties of the system because it is a measurement of the change between the initial and nal states of the system, which means calculating the change in enthalpy and entropy. 4. (a) They are both state functions (b) They both have extensive properties 5 a b TOSSO 4 20 4 ELT TOS 7.100J 274K T 263K LT anything less than263k 8 LT 7.1001 2711k T 263K LT anything less than263k