Entropy is defined as the degree of disorderliness of a system. The more orderly a system is, the more its entropy tends to zero.
Hence solid particles have the least entropy because solid particles do not translate. The entropy of liquid particles is greater than that of solid particles since liquid particles can translate. Gas particles have the highest entropy because gas particles move at a very high velocity owing to minimal intermolecular interaction.
Also, the heavier the molecules of a substance, the larger its molar entropy therefore, CH3CH2OH(g) exhibits the greatest entropy.
