Entropy

What is a spontaneous reaction?

A change that tends to occur of its own accord - rate of reaction may be slow that reaction seems not to occur

explain low entropy.

experienced by a system with atoms in fixed positions that have little or no freedom to move, eg solid.

explain highest entropy.

Highest entropy is experienced by a system whose atoms are free to move in any direction and move to any position, eg gas.

What is entropy?

Entropy is often described as the disorder in a system

How calculate standard entropy changes?

• ΔS = S product - S reactants

• units = JK–1mol–1

How to calculate Gibbs Free energy?

• ΔG = ΔH – TΔS

• ΔG is the change in Gibbs Free energy (kJ mol-1 )

• ΔH is the change in enthalpy (kJ mol-1 )

• T is the temperature (Kelvin)

• ΔS is the change in entropy (J K-1 mol-1 ) always /1000

How to know if a reaction is feasible?

∆G ≤ 0 reaction is feasible (negative value)

how do you make it more feasible / spontaneous?

• changing the temperature

Entropy table?