Why nonpolar solvent "picks up" water?

In summary, most solvents used in the laboratory have a shelf life and can potentially pick up small amounts of water from humidity over time. However, toluene is immiscible with water and therefore it is unlikely that water would solvate into this nonpolar solvent. There are ways to estimate the quality of the solvent after some time, but it is important to consider the perspective of the transfer process. In order to transfer hydrogen, the destination vessel needs to be inverted due to the nature of the atmosphere.
  • #1
Hyo X
101
11
Most solvents we use in the laboratory have some shelf life. Experimental example: Say you have a 4L bottle of anhydrous toluene and you regularly pour out/use small volumes of it over the course of a year. One year from opening date, you have 1L of toluene left.
Will this toluene still be "anhydrous" or will it have some small amount of water picked up from humidity in the atmosphere? Isn't toluene immiscible with water? So why would water solvate into a nonpolar solvent like this? is there a way to calculate/estimate the quality of the solvent after some time?
 
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  • #2
Hyo X said:
Will this toluene still be "anhydrous" or will it have some small amount of water picked up from humidity in the atmosphere? Isn't toluene immiscible with water? So why would water solvate into a nonpolar solvent like this? is there a way to calculate/estimate the quality of the solvent after some time?
No, and yes. No. Everything is soluble to some degree in everything else. No.
 
  • #3
When you transfer the solvent from one vessel to another you are not just pouring the solvent. You are also pouring atmosphere into the source vessel. It is a matter of perspective.

Try to pour hydrogen from one vessel to another in normal atmosphere. You need to have the destination vessel "upside down."

BoB

PS: see you can make a similar video with everything inverted with hydrogen.
 

Related to Why nonpolar solvent "picks up" water?

1. Why do nonpolar solvents attract and dissolve water?

Nonpolar solvents, such as oils and fats, have molecules that do not have a positive or negative charge. Water, on the other hand, is a polar molecule with a positive and negative end. When the nonpolar solvent comes into contact with water, the polar water molecules are attracted to the nonpolar solvent molecules. This attraction allows the nonpolar solvent to dissolve the water molecules and create a solution.

2. How does the polarity of water affect its interaction with nonpolar solvents?

The polarity of water is what allows it to form hydrogen bonds with other polar molecules. In the case of nonpolar solvents, the polar water molecules are not attracted to the nonpolar solvent molecules, but rather to each other. This makes it difficult for the nonpolar solvent to dissolve in water, but it can still form a solution due to the polar water molecules surrounding the nonpolar solvent molecules.

3. What makes nonpolar solvents better at picking up water compared to other solvents?

Nonpolar solvents are better at picking up water because of their similar nonpolar nature. This means that the nonpolar solvent molecules can easily mix and interact with the water molecules, allowing for a more efficient dissolving process. Additionally, nonpolar solvents tend to have a lower boiling point, making it easier for them to evaporate and leave behind the dissolved water molecules.

4. Can all nonpolar solvents dissolve water?

No, not all nonpolar solvents can dissolve water. This is because some nonpolar solvents have larger molecules or different chemical structures that do not allow them to effectively interact with water molecules. Additionally, the strength of the intermolecular forces between the nonpolar solvent and water can also affect their ability to dissolve in each other.

5. How does the size and shape of nonpolar solvent molecules affect their ability to pick up water?

The size and shape of nonpolar solvent molecules can greatly impact their ability to dissolve water. Smaller nonpolar molecules can more easily interact with water molecules, making them better at dissolving water. The shape of nonpolar molecules can also affect how they interact with water, with more symmetrical molecules being more efficient at dissolving water compared to asymmetrical molecules.

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