Qualitative Predictions about Entropy Entropy is the randomness of a system. At
ID: 901235 • Letter: Q
Question
Qualitative Predictions about Entropy
Entropy is the randomness of a system. At the molecular level, entropy can be described in terms of the possible number of different arrangements of particle positions and energies, called microstates. The more microstates the system has, the greater its entropy.
Microstates depend on molecular motion. Molecules may undergo three different types of motion: translational motion, vibrational motion, and rotational motion. During translational motion, the entire molecule moves in one direction. During vibrational motion, atoms in a molecule move toward and away from one another. During rotational motion, molecules rotate or spin. The number of molecules, the space available for the molecules, and the energy available to the molecules will impact the number of microstates.
Another way of looking at entropy is that the universe is moving toward a broader distribution of energy. The universe has a constant amount of energy as stated in the first law of thermodynamics. The universe started with low entropy (concentrated in the moment before the "big bang") and the entropy has since been constantly increasing by distributing this energy. Heat distribution from high temperature to low temperature is a another example of this phenomenon.
Explanation / Answer
Two general rules to provide the answer
1) The entropy of the liquid is lesser than the entropy of the gas, entropy of the gas increases with increase in temperature and volume
2) The higher the amount of disorder in the molecule, the higher will be the entropy for that molecule
Hence the correct order will be
1 mol of CCl4 gas at 273K and 40L > 1 mole of Cl2 gas at 273K and 40L > 1 mole of argon gas at 273K and 40L > 1 mole of argon gas at 273K and 20L > 0.5 moles of argon gas at 273K and 20L > 0.5 moles of argon gas at 100K and 20L > 0.5 moles of liquid argon at 100K