1. Entropy and Chemical Reactions

2. Spontaneity Basically the law of conservation of energy
energy can be neither created nor destroyed
i.e., the energy of the universe is constant
the total energy is constant
energy can be interchanged
e.g. potential energy (stored in chemical bonds) can be converted to thermal energy in a chemical reaction
CH4 + O2 --> CO2 + H2O + energy
Doesn’t tell us why a reaction proceeds in a particular direction
© Copyright All rights reserved.

3. Entropy Randomness or disorder of a system
Increases as temperature increases
Increases as you increase agitation
Increases as you add energy to the system
© Copyright All rights reserved.

4. Entropy Symbol: S A measure of randomness or disorder
The natural progression is from order to disorder
It is natural for disorder to increase
Entropy is a thermodynamic function
Describes the number of arrangements that are available to a system in a given state
© Copyright All rights reserved.

5. Entropy
The greater the number of possible arrangements, the greater the entropy of a system, i.e., there is a large positional probability.
The positional probability or the entropy increases as a solid changes from a liquid or as a liquid changes to a gas.
© Copyright All rights reserved.