How volatile impurity affects boiling point of a liquid?

AI Thread Summary
The discussion centers on the effects of impurities on the boiling point of liquids, specifically addressing non-volatile and volatile impurities. Non-volatile impurities raise the boiling point because they reduce the vapor pressure of the solvent, requiring a higher temperature to reach the external pressure, as explained by Raoult's law. In contrast, the presence of volatile impurities can increase vapor pressure since they can vaporize themselves, potentially lowering the boiling point. The conversation emphasizes the relationship between vapor pressure, temperature, and boiling point, while also acknowledging the importance of understanding these concepts for better comprehension of physical chemistry.
Brwahussen
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I know that non volatile impurities increases the boiling point of a liquid.

Does volatile impurity decreases the boiling point? How?
 
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In general more volatile things boil first, don't they?

What is the definition of the boiling point? Why does the presence of non-volatile impurity increase the BP temperature? (hint: Raoult's law). Can you extend this line of thinking?
 
Borek said:
In general more volatile things boil first, don't they?

What is the definition of the boiling point? Why does the presence of non-volatile impurity increase the BP temperature? (hint: Raoult's law). Can you extend this line of thinking?
Because the presence of impurities will block more molecules to jump to gaseous state so the vapore pressure will decrease, hence more energy is needed to elevate vapore pressure to environment pressure and higher boiling point is resulted.

So, does presense of volatile impurity will cause higher vapore pressure? Because it vaporizes it by itself

[sorry if my English is bad]
 
Brwahussen said:
Because the presence of impurities will block more molecules to jump to gaseous state so the vapore pressure will decrease

OK

hence more energy is needed to elevate vapore pressure to environment pressure and higher boiling point is resulted.

It is not exactly about energy (although in a way you are right, you need energy to heat up the mixture), more like you need a higher temperature so that the partial pressure of the solvent becomes equal to the external pressure. But in general you are on the right track. Note that is pretty easy to show using Raoult's law (try!).

So, does presense of volatile impurity will cause higher vapore pressure? Because it vaporizes it by itself

Yes.

[sorry if my English is bad]

Actually it is not just bad, it is atrocious :wink: But everyone has to start somewhere.
 
Borek said:
OK
It is not exactly about energy (although in a way you are right, you need energy to heat up the mixture), more like you need a higher temperature so that the partial pressure of the solvent becomes equal to the external pressure. But in general you are on the right track. Note that is pretty easy to show using Raoult's law (try!).
Yes.
Actually it is not just bad, it is atrocious :wink: But everyone has to start somewhere.
Thanks!
:)

And I will keep improving my english ;).
 
Brwahussen said:
And I will keep improving my english ;).

Popracuj popracuj, warto.
 
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