Should Toluene be clear or cloudy white?

  • Thread starter Thread starter n0_3sc
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the observation of toluene turning cloudy white after being stored in a non-sealed bottle. Participants explore potential causes for this phenomenon, including contamination and interactions with materials, while considering the implications for the purity of the toluene solution.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant notes that the cloudiness indicates possible contamination, questioning whether the bottle was dry.
  • Another suggests that humidity from the air or residual moisture in the bottle could be responsible for the cloudiness.
  • A participant confirms that distilled water can act as a contaminant, emphasizing that even small amounts can affect organic solvents like toluene.
  • Concerns are raised about the interaction between water and toluene, with one participant suggesting that a mixture might not form a suspension without stirring.
  • Another participant introduces the idea that the cloudiness could be due to the toluene being in contact with plastic, which may have reacted with the solvent.
  • It is mentioned that toluene is a strong solvent that can dissolve certain plastics, potentially leading to the observed cloudiness.

Areas of Agreement / Disagreement

Participants express differing views on the cause of the cloudiness, with some attributing it to contamination from water and others suggesting interactions with plastic. No consensus is reached regarding the definitive cause of the phenomenon.

Contextual Notes

Participants discuss the implications of residual moisture and the effects of plastic on toluene, but the specific conditions under which these interactions occur remain unresolved.

n0_3sc
Messages
238
Reaction score
1
I have very little background in chemistry.
A clear sample of toluene was poured into a non sealed bottle and after several hours it turned cloudy white.
Is this normal?
Why does this happen?
It is still a clean solution of toluene right?
 
Chemistry news on Phys.org
It shouldn't, there is some contamination. Was the bottle dry?
 
Or the bottle was not dry (or contained something that mixed with toluene) or the liquid has absorbed humidity from air.
 
Hey,

The bottle was rinsed out with distilled water but not thoroughly dried. It sits in a near dust-free environment where temperature and humidity are controlled. The bottle had no previous chemical substance in it. Not for >3 years that I know off.
 
n0_3sc said:
Hey,

The bottle was rinsed out with distilled water but not thoroughly dried. It sits in a near dust-free environment where temperature and humidity are controlled. The bottle had no previous chemical substance in it. Not for >3 years that I know off.

So it could be the little amount of water still present in the bottle after rinsing out.
 
really?? distilled water can be a contaminant?
 
Yes, water can be a contaminant. Given that toluene's solubility in water is quite minimal, even a tiny bit of water can serve as a contaminant. Many organic solvents - including toluene - are typically sold as "dry" solvents (water-free or nearly so), since even a small amount can screw up someone's work.
 
n0_3sc said:
really?? distilled water can be a contaminant?

Let's see - is water a chemical?
 
I'm not quite certain if water and toluene would mix to form a suspension you might want to observe a mixture without stirring it ; should find two immiscible phases. From my experience a small amount of water in certain organic substances forms a cloudy suspension with stirring ; at times at 2% however it should be higher for toluene. Surfactants can cause reverse miscelle formation with water and toluene also.
 
  • #10
I think I found the cause of the problem (along with water). The toluene was sandwiched between two transparent pieces of plastic. Apparently you can't place these chemicals on plastic due to some effect? The plastic turned all opaque and "cloudy white".
 
  • #11
Toluene is a pretty good solvent, it will penetrate many plastics and it will dissolve them to some extent.
 

Similar threads

Replies
6
Views
5K
  • · Replies 21 ·
Replies
21
Views
6K
  • · Replies 14 ·
Replies
14
Views
3K
Replies
5
Views
1K
Replies
0
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 15 ·
Replies
15
Views
9K
  • · Replies 19 ·
Replies
19
Views
10K