Entropy

EntropyChapter 5: Energetics and thermodynamicsIb higher level chemistryEntropyEntropy can be expressed in several ways:

-degree of order or disorder in a system

-number of ways of distributing energy among particlesEntropy as DisorderThe more disordered a system, the greater its entropy

The more ordered a system, the lower its entropy

Entropy as DisorderA messy room with clothes and books all over the floor would be disordered and have high entropy.

A neat room with folded clothes and stacks of book neatly against the wall would be ordered and have low entropy.

High entropy

Low entropyEntropy as Energy DistributionLets say we have a gas.

Each particle has kinetic energy, but some have more than others. Temperature measures the average kinetic energy of these particles.

Entropy can be defined as the number of ways energy is split between particles. The more ways energy can be split, the greater the entropy.Factors affecting entropyEnthalpy: the greater the amount of energy, the more ways it can be distributed between particles and the greater the entropy(a gas has greater enthalpy than a liquid, and a liquid has greater enthalpy than a solid)

Number of particles: the greater the number of particles, the more ways energy can be distributed between them

Change of state: related to enthalpy