Entropy

1st case

5th case

3rd case

4th case

2nd case

Lamya AlJehani
Najla AlHusain
Yara AlKahtani
11D

Entropy changes associated with changes in state. Entropy increases as a substance changes from a solid to a liquid and from a liquid to a gas.

ΔS(system) is positive

ex: vaporization of water

The dissolving of a gas in a solvent always results in a decrease in entropy. Therefore, when a gas is dissolved in a liquid it limits its randomness and movement causing a decrease in entropy

ΔS(system) is negative

ex: dissolving of carbon dioxide in soda

Assuming no change in physical state occurs, the entropy of a system usually increases when the number of gaseous product particles is greater than the number of gaseous reactant particles

ΔSsystem is positive

ex: two molecules of gas react and three molecules of gas are produced.

Entropy increases when a solid or liquid dissolves in a solvent. When the solute dissolves in the solvent, its particles become more free.

ΔS(system) is positive.

ex: dissolving of sodium chloride in water.

The random motion of the particles of a substance increases as its temperature increases. When temperature increases, kinetic energy increases and particles move more freely causing entropy to increase.

ΔS(system) is positive.

ex: increasing temperature