thermodynamics
THERMODYNAMICS FLASHCARDS
1.
Q: What is the First Law of Thermodynamics?
A: Energy cannot be created or destroyed. \Delta U = q + w
2.
Q: What does q represent in thermodynamics?
A: Heat transferred into or out of the system.
3.
Q: What does w represent in thermodynamics?
A: Work done on or by the system.
4.
Q: What is enthalpy (H)?
A: Heat content at constant pressure: H = U + PV
5.
Q: What is entropy (S)?
A: A measure of disorder or randomness.
6.
Q: What is the Second Law of Thermodynamics?
A: The total entropy of the universe always increases for a spontaneous process.
7.
Q: What is Gibbs Free Energy?
A: G = H - TS, determines spontaneity.
8.
Q: What does \Delta G < 0 mean?
A: The reaction is spontaneous.
9.
Q: What does \Delta G = 0 mean?
A: The system is at equilibrium.
10.
Q: What is the formula for heat transfer with no phase change?
A: q = mc\Delta T
11.
Q: What is Hess’s Law?
A: The total enthalpy change of a reaction is the sum of the changes for individual steps.
12.
Q: What’s the sign of \Delta H in an exothermic reaction?
A: Negative.
13.
Q: What is the unit of entropy (S)?
A: J/mol·K
14.
Q: What does a positive \Delta S mean?
A: Increased disorder.
15.
Q: At what point is a phase change occurring?
A: When temperature remains constant while heat is added or removed.