Can Small Amounts of Chemicals Lower Water's Boiling Point?

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Discussion Overview

The discussion revolves around the question of whether small amounts of chemicals can lower the boiling point of water. Participants explore various interpretations of the question, including the definitions of boiling point and the effects of different substances on water's boiling temperature.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants suggest that the boiling point of water is defined at one atmosphere, while others note that it is now referred to as the normal boiling point, which is pressure-dependent.
  • One participant argues that it is impossible to lower the boiling point of water without significant amounts of another chemical, excluding catalytic amounts.
  • Another participant mentions that certain mixtures, such as vodka, have lower boiling points than pure water, indicating that the question may involve mixtures.
  • Some participants discuss the effects of removing ions from tap water, suggesting that this could lower the boiling point slightly due to colligative properties, although this may not align with the original intent of the question.
  • There are references to specific examples of chemical mixtures that can lower the boiling point of water, such as benzyl alcohol and cyclohexanol, but the amounts required for significant changes are noted to be substantial.
  • One participant points out that many substances can raise the boiling point, depending on their vapor pressure.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of lowering water's boiling point with small amounts of chemicals. There is no consensus on the interpretation of the question or the conditions under which boiling point changes occur.

Contextual Notes

The discussion highlights the ambiguity in the original question regarding the definition of boiling point and the conditions under which it may change. There are also unresolved assumptions about the types and amounts of chemicals being considered.

Blenton
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Is there any catalyst or substance that can do this?
 
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A lot depends on what you mean by "water". Obviously you are ready to accepts some mixture - vodka is such a mixture, and it boils at much lower temperature.

That is assuming by "lowing" you meant "lowering".

So short question, so many meanings :smile:
 
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Hmmm I seem to remember that in my time the boiling point was defined as the boiling temperature of the pure liquid at one atmosphere (or sea level). But it seems to be defined as the normal boiling point now

Any fluid boils at reduced temperatures at reduced ambient pressure. That limited us from flying above 62.000 feet, then blood starts to boil.
 
I suppose the question is meant to be understood as "lower boiling point after something has been added all other things being equal". But it is as vague as a question can be.

Andre said:
Hmmm I seem to remember that in my time the boiling point was defined as the boiling temperature of the pure liquid at one atmosphere (or sea level).

I think you have just forgot that part about "normal" or "standard" - after all, boiling point was always pressure dependent :wink:
 
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As Borek wrote, is impossible to lower the BP of water without significant amounts of another chemical (so, "catalythic" amounts are excluded).
Here there are some values of BP of mixes water + other liquid:
http://en.wikipedia.org/wiki/Azeotrope_(data )

From these data you see how is difficult to lower the BP of water: if you want to use little amounts of chemicals, you could, e.g. use 9% benzyl alcohol, but the BP lowers of 0.1°C only.; or you could use cyclohexanol and you lower the BP of 2.2°C, but you have to use at at 20%...
 
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Note that many substances will not lower, but raise the boiling point; that depends on the vapor pressure of the substance.
 
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If you mean regular tap water, I would imagine that removing some of the ions (Ca2+, Mg2+, etc.) would lower the boiling temperature slightly because of colligative properties. You can do this with a Brita filter, but the boiling point depression depends on the initial concentrations of the ions in this case. I'm pretty sure this isn't what OP meant though.
 
Hmm yes it was what I thought. It would probably against conservation of energy unless for some instance energy going into boiling water was wasted by a large degree.

I suppose the question is meant to be understood as "lower boiling point after something has been added all other things being equal". But it is as vague as a question can be.

Sorry I didn't notice the title, my meaning of Lowering the boiling point of water.

As Borek wrote, is impossible to lower the BP of water without significant amounts of another chemical (so, "catalythic" amounts are excluded).
Here there are some values of BP of mixes water + other liquid:
http://en.wikipedia.org/wiki/Azeotrope_(data )

From these data you see how is difficult to lower the BP of water: if you want to use little amounts of chemicals, you could, e.g. use 9% benzyl alcohol, but the BP lowers of 0.1°C only.; or you could use cyclohexanol and you lower the BP of 2.2°C, but you have to use at at 20%...

Interesting, but it does seem that for such a large quantity only a small gain is achieved.
 
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