Physical Chemistry Lec 1

CHM1205 Lec 1-2

Physical Chemistry

Physical chemistry studies matter and its changes during chemical reactions. It combines principles from physics and chemistry to examine atoms, molecules, and their interactions.

Importance of Physical Chemistry

• Helps us understand why certain processes have a natural tendency to occur (spontaneously)

• Helps us understand the reason for change

• Conditions we can manipulate so as to promote a desirable change

• Predict rate of change and the extent of change

Thermodynamics

It is the physics of heat, work, enthalpy, and entropy changes in relation to the spontaneity of processes.

Zeroth Law of Thermodynamics

If two systems, A and B, are in thermal equilibrium with a third system, C, then A and B are in thermal equilibrium with each other.

The First Law of Thermodynamics

Energy can not be created or destroyed but is converted from one form to another.

The total energy of the universe is _______!

Constant

Energy “universe” =

Energy of system + Energy of surroundings

First Law equation

∆U = q + w

•u is

•q is

•w is

internal energy

heat exchange in the system

work done on/by system