Rubberband Entropy

[MedPR]

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This is from TBR and I can't wrap my head around it.

"This means that as the rubber band goes from stretched to relaxed, it becomes more disordered. This may seem odd at first, but when you consider any net (like a tennis net or a volleyball net), you should note that when it is stretched, it is orderly. When bundled up, it is disordered. In essence, a rubberband is a microscopic net."

It makes sense for the nets, but not for the rubberband. Doesn't increasing volume while maintaining a constant number of particles increase entropy? And when you stretch a rubberband, aren't you increasing its volume?

 

[milski]

This is from TBR and I can't wrap my head around it.

"This means that as the rubber band goes from stretched to relaxed, it becomes more disordered. This may seem odd at first, but when you consider any net (like a tennis net or a volleyball net), you should note that when it is stretched, it is orderly. When bundled up, it is disordered. In essence, a rubberband is a microscopic net."

It makes sense for the nets, but not for the rubberband. Doesn't increasing volume while maintaining a constant number of particles increase entropy? And when you stretch a rubberband, aren't you increasing its volume?

The molecules of the rubber band are similar to the ropes of the tennis net. When the band is at rest, the molecules can be oriented in any random way. The more you stretch it, the more they line up with each other to allow for the increased length.

There should not be any significant volume change when you extend the band - it will increase in length but compensate for that by lower width/thickness.

 

[chiddler]

When the net/rubber band is relaxed, it's bundled up in a big bunch of rubberness. No distinct order because it's all messy. When it is stretched, it is more discernible, distinct, and orderly.

It takes energy input to make order which is why it takes energy to stretch the rubber band.

This was my first impression; correct me if i'm wrong. I'm not sure what to make out of what you had written regarding volume.

 

[MedPR]

The molecules of the rubber band are similar to the ropes of the tennis net. When the band is at rest, the molecules can be oriented in any random way. The more you stretch it, the more they line up with each other to allow for the increased length.

There should not be any significant volume change when you extend the band - it will increase in length but compensate for that by lower width/thickness.

When the net/rubber band is relaxed, it's bundled up in a big bunch of rubberness. No distinct order because it's all messy. When it is stretched, it is more discernible, distinct, and orderly.

It takes energy input to make order which is why it takes energy to stretch the rubber band.

This was my first impression; correct me if i'm wrong. I'm not sure what to make out of what you had written regarding volume.

Duh. Thanks guys. I swear sometimes MCAT makes my common sense disappear.