Solubility of Non polar substances in water

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SUMMARY

Water can dissolve non-polar substances such as O2 and CO2, despite the common belief that only polar molecules dissolve in water. CO2, while non-polar, reacts with water to form carbonic acid, which is a reversible process considered dissolution. The discussion highlights that dissolution can involve coordination rather than irreversible covalent bond formation, as seen with substances like K, NaH, AlCl3, and SOCl2. Understanding these interactions is crucial for a comprehensive grasp of solubility in chemistry.

PREREQUISITES
  • Basic understanding of molecular polarity
  • Knowledge of chemical reactions and reversible processes
  • Familiarity with coordination chemistry
  • Concept of solubility and dissolution in physical chemistry
NEXT STEPS
  • Research the process of carbonic acid formation from CO2 and water
  • Explore the concept of solvation and its role in dissolution
  • Study the properties of triplet oxygen and its interactions with water
  • Investigate the solubility of ionic compounds in water and their dissociation
USEFUL FOR

Chemistry students, physical chemists, and anyone interested in the solubility of gases and non-polar substances in water.

Kaneki123
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Water can dissolve O2 and CO2, both of which are non-polar...According to my understanding, water can only dissolve molecules which have polarity in their structure( like salt or sugar)...Oxygen gas is non-polar due to same atoms...I am not sure about CO2 but I think it is non-polar due to equal attraction of electrons...So why can water dissolve these two substances?
 
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To some extent everything dissolves in everything.

CO2 is a bit different, as it not just dissolve.
 
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Borek said:
To some extent everything dissolves in everything.

CO2 is a bit different, as it not just dissolve.
This.

CO2 turns into carbonic acid in water
 
HAYAO said:
This.

CO2 turns into carbonic acid in water
Then it would not exactly be 'dissolving''...right??
 
Kaneki123 said:
Then it would not exactly be 'dissolving''...right??
well it is considered as dissolution.
 
The reaction of CO2 with water is reversible, so I suppose it's 'OK' to consider it as dissolution.
In most cases however I suspect there should be no irreversible formation of covalent bonds, at most coordination (water solvates the molecules, so they separate and macroscopically the added substance 'disappears'), to be able to call it 'dissolution'. I'm sure physical chemists have a better definition; this is a messy organic chemist's point of view :wink:

Examples of substances that will 'disappear' in water but are actually reacting (irreversibly, I think it's safe to say) rather than 'dissolving'.

K
NaH
AlCl3
SOCl2 (I guess some may even dissolve initially, but it won't hang around very long)
...
 
Kaneki123 said:
Water can dissolve O2 and CO2, both of which are non-polar...According to my understanding, water can only dissolve molecules which have polarity in their structure( like salt or sugar)...Oxygen gas is non-polar due to same atoms...I am not sure about CO2 but I think it is non-polar due to equal attraction of electrons...So why can water dissolve these two substances?
CO2 is nonpolar b/c it is a linear molecule with diametrically opposing dipoles at 180o bond angle. => O=C=O and Oxygen (O2) is a triplet (dipole = 0) :O=O: that coordinates with Hydrogen in water ( ---:O=O:---H-O-H---:O=O:---). see also https://en.wikipedia.org/wiki/Triplet_oxygen
 
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