Why do gases become more soluble at lower temperatures?

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Discussion Overview

The discussion revolves around the solubility of gases in various solvents at different temperatures, particularly focusing on the case of the antarctic crocodile icefish and its ability to transport oxygen in dissolved form. Participants explore the underlying principles and laws of physics that may explain why gases become more soluble at lower temperatures.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant notes that lower temperatures favor the condensation of gases, suggesting that entropy plays a role in gas solubility.
  • Another participant argues that the relationship between gas solubility and temperature is not a general rule, as some gases are more soluble in certain solvents at lower temperatures, citing oxygen in water as an example.
  • A participant highlights that the solubility of oxygen in water increases as the temperature decreases, but this is presented as a specific case rather than a universal principle.
  • It is mentioned that the solubility of oxygen in water is an exception that applies only within a limited temperature range.
  • Another participant points out that water is not the only solvent, noting that the solubility of oxygen in alcohol increases with temperature, indicating that a general explanation may overlook important nuances.

Areas of Agreement / Disagreement

Participants express differing views on the generality of the principle that gases become more soluble at lower temperatures. While some acknowledge specific cases where this holds true, others argue that exceptions exist, leading to an unresolved discussion regarding the applicability of the principle across different gases and solvents.

Contextual Notes

The discussion highlights limitations in the generalization of gas solubility principles, particularly regarding the dependence on specific solvents and the conditions under which gases dissolve.

lald6103
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Hello

I recently read that the antarctic crocodile icefish (Channichthyidae) has colourless blood because it lacks haemoglobin. Apparently it can transport large amounts of oxygen around the blood in dissolved form because of its low body temperature (-1.8 to 2 degrees C).

I was just after an explanation of this? What law(s) of physics state(s) that a gas is more soluble at lower temperatures?

Regards

Louis
 
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Generally speaking entropy is at work; lower T favors condensation of gases.
 
It's not a general rule.
Some gases are more soluble in some solvents at lower temperatures.
An example is oxygen dissolved in water.

It's a case by case thing. Similar to some chemical reactions release energy (exothermic) and others need energy from environment (endothermic).
The solubility case depends also on what happens when the gas dissolves: heat released or absorbed.
 
He solubility in water is the only exception of which I'm aware, and that's only through a limited T range.
 
Water is not the only solvent.
The solubility on oxygen in alcohol increases with temperature.
So a "general" explanation like lower temperature favors condensation of gases is missing something.
 

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