Chemistry

Question 1

What is thermodynamics?

Answer 1

The study of heat changes associated with chemical reactions.

Question 2

What are the three types of thermodynamic systems?

Answer 2

1. Open system – Exchanges both energy and matter.
2. Closed system – Exchanges only energy, not matter.
3. Isolated system – Does not exchange energy or matter.

Question 3

What is the first law of thermodynamics?

Answer 3

Energy can neither be created nor destroyed; it remains constant in an isolated system.
Formula: ΔU = q + w

Question 4

What are intensive and extensive properties?

Answer 4

Intensive properties: Independent of the amount of matter (e.g., temperature, pressure, density).
Extensive properties: Depend on the amount of matter (e.g., mass, volume, internal energy).

Question 5

What are state functions and path functions?

Answer 5

State functions depend only on the initial and final state (e.g., T, P, V, U, H, S, G).
Path functions depend on the path taken (e.g., heat (q) and work (w)).

Question 6

Name four thermodynamic processes.

Answer 6

1. Isothermal process – Constant temperature (ΔT = 0).
2. Isobaric process – Constant pressure.
3. Isochoric process – Constant volume (ΔV = 0).
4. Adiabatic process – No heat exchange (q = 0).

Question 7

What is enthalpy (H)?

Answer 7

The total heat content of a system.
Formula: H = U + PV

Question 8

What is Hess’s Law?

Answer 8

The total enthalpy change of a reaction is the same whether it occurs in one or multiple steps.

Question 9

What is Gibb’s free energy equation?

Answer 9

ΔG = ΔH - TΔS

Question 10

How do you determine spontaneity using Gibbs free energy?

Answer 10

ΔG < 0: Spontaneous process.
ΔG = 0: Equilibrium.
ΔG > 0: Non-spontaneous process.