Question

Rank these systems in order of decreasing entropy. Rank from highest to lowest entropy. To rank items as equivalent overlap them. 

1 mol of hydrogen peroxide gas at 273K and 40L 

1/2 mol of  helium gas at 100 K and 20 L 

1 mol of chlorine gas at 273K and 40 L 

1 mol of chlorine gas at 273K and 40 L 

1/2 mol of helium gas at 273K and 20 L 

1 mol of helium gas at 273K and 20 L 

1/2  mol of liquid helium  at 100K

Answer 1

Concepts and reason

Entropy

Entropy is defined as the measure of disorder (randomness) of molecules such as helium, chlorine, and hydrogen peroxide in a system. It is a thermodynamic state function.

Fundamentals

Entropy

The entropy of molecules increases with the changing of the physical states of matter from solid to gas due to internal degrees of freedom of motions.

The entropy of molecules tends to increase with the increase of the following factors:

oTemperature (T)

oVolume (V)

oNumber of molecules (mole, n)

oSize of the molecules

Out of all, the lowest entropy is

The systems are in the decreasing entropy order:

For different gases at same 273 K and same 40 L:

For all systems:

Ans: