The decreasing order of entropy is as follows:
Further explanation:
In thermodynamics, criteria for spontaneity depend upon a thermodynamic parameter called entropy. This entropy is essentially the measure of randomness or disorder associated with the systems. Any chemical reaction is feasible or spontaneous only if the entropy change associated with the system is positive. Hence there is always a natural tendency for the system to become more chaotic or disordered with time.
Entropy is an extensive property hence the greater the number of particles greater is the entropy. Thus methane that contains the maximum number of atoms has greater entropy than hydrogen gas that contains only two hydrogen atoms at same temperature. Similarly hydrogen gas atand has more entropy thanof helium gas at the same temperature and pressure as helium is a monoatomic gas.
In general, the gaseous molecules are always in random motion hence the extent of disorder is maximum in gases followed by the liquids where the order is intermediate and the most ordered one are the solids whose molecules are rigid and have least intermolecular spaces between them. This explains why the liquid helium has the least disorder and hence the least entropy compared to all other gases. Thus methane that contains the maximum number of atoms has greater entropy than hydrogen gas that contains only two hydrogen atoms at the same temperature.
The entropy also varies with temperature and volume. An increase in temperature favors the chaotic movement of molecules by increasing their kinetic energies. Thus the randomness also increases with high temperature. Further greater the volume occupied by a molecule more is the intermolecular spaces available for the random motion. Hence the helium gas at higher volume has greater entropy than same amount of helium that occupies lower volume .
Learn more:
1. Calculation of entropy of a reaction: brainly.com/question/12442928
2. Entropy changes in different states of matter: brainly.com/question/12632987
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Thermodynamics
Keywords: Thermodynamics,spontaneity, entropy,randomness,temperature,volume,kinetic energy,intermolecular spaces and disorder.