Introduction to Thermodynamics Physical Chemistry

Temperature

1. when a hotter and a colder bodies are brought in contact, heat flows from the hotter body to the colder body.

2. at thermal equilibrium, two bodies in contact have equal temperatures and there is not net heat flow from one body to the other.

3. in thermodynamics, there is the lowest temperature (the absolute zero, T=0-the absolute scale of temperature)

SI unit: 1 K

k_B=1.38064852×10^-23 J/K

∆1˚C=∆1K

Pressure

P=F/A

SI unit: 1Pa = 1N/m²

1 bar = 10⁵ Pa

1 atm = 101325 Pa = 1.01325 bar

1 mmHg = 1 torr

1 atm = 760 torr

mechanical equilibrium p₁=p₂

Work

transfer of energy that causes uniform motion of atoms in the surroundings

always specify the conditions (const T, p, or const T, V)

Heat

transfer of energy that causes random motion of atoms in the surroundings

always specify the conditions (const T, p, or const T, V)

Open System

Allow exchange of energy and matter

Closed System

Allow exchange of energy but NOT matter

Isolated System

No exchange of energy or matter

The Universe

= the system+ the surroundings

What kind of system is a biological cell?

Open System

Sign Convention

(Point of view of the system)

Heat absorbed by the system q>0 endothermic

Heat released from the system q<0 exothermic

Work done on the system w>0

Work done by the system w<0

Diathermal Wall

Allows for heat transfer

Heat Engines

Heat Engine P vs V graph

Isothermal Process

Absolute Zero