Residual Entropy

[Robert Tran 1B]

What is residual entropy and how does it arise?

[nehashetty_2G]

I believe residual entropy is the energy that remains even when a sample is brought to 0 Kelvin caused by disorder in the sample.

[Labiba Sardar 2A]

How is residual entropy different from the regular entropy that we've been using for any other problem (for example, like delta S)?

[Labiba Sardar 2A]

I believe residual entropy is the energy that remains even when a sample is brought to 0 Kelvin caused by disorder in the sample.

What causes there to still be some energy, allowing it to have some disorder? I thought that at 0 Kelvin, all particles stop moving, therefore there wouldn't be any disorder.

[claudia_1h]

What causes there to still be some energy, allowing it to have some disorder? I thought that at 0 Kelvin, all particles stop moving, therefore there wouldn't be any disorder.

At 0 K, there is no contribution to entropy from rotational/thermal motion. However, there is, for most molecules, residual entropy that comes from the general inherent disorder of the molecule. A perfectly ordered molecule at 0 K would have 0 residual entropy and therefore 0 overall entropy.

[Labiba Sardar 2A]

What causes there to still be some energy, allowing it to have some disorder? I thought that at 0 Kelvin, all particles stop moving, therefore there wouldn't be any disorder.

At 0 K, there is no contribution to entropy from rotational/thermal motion. However, there is, for most molecules, residual entropy that comes from the general inherent disorder of the molecule. A perfectly ordered molecule at 0 K would have 0 residual entropy and therefore 0 overall entropy.

So does that mean that ideally, there would be 0 overall entropy at 0 K, but it's more realistic for there to be some disorder for most molecules at 0 K?