# Adjusting boiling points if liquid? **URL:** \ **Category:** Factual Questions\ **Created:** [December 21, 2020, 9:23pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570 "2020-12-21T21:23:03Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [December 21, 2020, 9:23pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/1 "2020-12-21T21:23:03Z")
Assume atmospheric pressure. Is there a way I could create a liquid compound (not necessarily water but water would be preferred) that would boil at very specific points by adding another chemical or compound to it. If so does anyone know what chemicals I would be using? Looking for temps up to about 300 degrees. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [December 21, 2020, 9:45pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/2 "2020-12-21T21:45:56Z")
Assuming the water can absorb enough, the right quantity of salt should be able to raise it up to 300. Also, 300 C or F? Edit: Turns out it takes a lot of salt to raise the boiling point of water by a very small amount. So probably not salt. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [December 21, 2020, 9:53pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/3 "2020-12-21T21:53:03Z")
Maybe try mixing in ethylene glycol (antifreeze), it appears to have a boiling point of 386.6F on it’s own. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 21, 2020, 9:54pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/4 "2020-12-21T21:54:38Z")
Pure (98.2%) glycerol boils at 290 °C (554 °F). To lower that to a specific point, just add the appropriate amount of water. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [December 21, 2020, 9:55pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/5 "2020-12-21T21:55:08Z")
I should have thought of that, spent my life as a mechanic. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [December 21, 2020, 9:56pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/6 "2020-12-21T21:56:11Z")
Excellent!!! Thank you. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [December 21, 2020, 10:19pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/7 "2020-12-21T22:19:00Z")
But I assume you’re aware that if you have a mixture of two liquids, although the boiling point will be intermediate, more of the component with the lower boiling point will boil off, changing the composition of the remaining mixture and thus steadily raising the boiling point of the mixture. > **[Raoult's Law and ideal mixtures of liquids](https://www.chemguide.co.uk/physical/phaseeqia/idealpd.html)** > > Explains how Raoult's Law applies to cases of two volatile liquids which form an ideal mixture. It explains how a phase diagram for such a mixture is built up and how to interpret it. > **[Fractional distillation](https://en.wikipedia.org/wiki/Fractional_distillation)** > > Pages for logged out editors learn more > > Fractional distillation is the separation of a mixture into its component parts, or fractions. Chemical compounds are separated by heating them to a temperature at which one or more fractions of the mixture will vaporize. It uses distillation to fractionate. Generally the component parts have boiling points that differ by less than 25 °C (45 °F) from each other under a pressure of one atmosphere. If the difference in boiling points is greater tha... ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [December 22, 2020, 12:58pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/8 "2020-12-22T12:58:04Z")
You have to scroll down a bit, but there’s a table of boing points for the binary mixture here: > **[Ethylene Glycol Heat-Transfer Fluid Properties](https://www.engineeringtoolbox.com/ethylene-glycol-d_146.html)** > > Properties like freezing point, viscosity, specific gravity and specific heat of ethylene glycol based heat-transfer fluids, or brines. It’s not very granular though. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [December 22, 2020, 1:11pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/9 "2020-12-22T13:11:58Z")
> [@Riemann](#): > > But I assume you’re aware that if you have a mixture of two liquids, although the boiling point will be intermediate, more of the component with the lower boiling point will boil off, changing the composition of the remaining mixture and thus steadily raising the boiling point of the mixture. I’ve got a candy recipe similar to **[this one](https://www.allrecipes.com/recipe/268587/honeycomb-toffee/)**, which tells you to boil a mix of corn syrup, sugar, and/or water while you monitor the temperature, which changes over time as the water evaporates. The recipe tells you to stop boiling when the temperature hits a predetermined value, at which point the water content is at the desired level. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [December 22, 2020, 1:43pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/10 "2020-12-22T13:43:18Z")
> [@Riemann](#): > > But I assume you’re aware that if you have a mixture of two liquids, although the boiling point will be intermediate, more of the component with the lower boiling point will boil off Nitpick: This is essentially correct with the caveat viz-a-viz of azetropes. You can get a azetrope of two different liquids where this will not happen. The composition of the vapor will be the same as the liquid and hence you cannot separate them by traditional distillation. For example, you cannot make pure ethyl alcohol by traditional distillation. > **[Azeotrope tables](https://en.m.wikipedia.org/wiki/Azeotrope_tables)** > > This page contains tables of azeotrope data for various binary and ternary mixtures of solvents. The data include the composition of a mixture by weight (in binary azeotropes, when only one fraction is given, it is the fraction of the second component), the boiling point (b.p.) of a component, the boiling point of a mixture, and the specific gravity of the mixture. Boiling points are reported at a pressure of 760 mm Hg unless otherwise stated. Where the mixture separates into layers, values are ... ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [December 22, 2020, 2:17pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/11 "2020-12-22T14:17:54Z")
> [@Riemann](#): > > But I assume you’re aware that if you have a mixture of two liquids, although the boiling point will be intermediate, more of the component with the lower boiling point will boil off, changing the composition of the remaining mixture and thus steadily raising the boiling point of the mixture I was wondering about that. This would be going for about 24 hours at a time so it would be an issue. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [December 22, 2020, 2:35pm UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/12 "2020-12-22T14:35:14Z")
> [@HoneyBadgerDC](#): > > I was wondering about that. This would be going for about 24 hours at a time so it would be an issue Please check the azetropes above, you can pick one that suits your need. If you are using this to treat your bows, please note that the water coming out of the wood would change the concentration and hence the boiling point. The other option is to use pressure control (please understand the risks of doing this). You will need about 15 psig pressure to change the water boiling temperature to 300F. Please have a relief valve in the system. You can also look into a silicone oil bath which stays liquid to about 360F. You can control the temperature with an electrical controller. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [December 23, 2020, 1:11am UTC](https://boards.straightdope.com/t/adjusting-boiling-points-if-liquid/928570/13 "2020-12-23T01:11:57Z")
> [@am77494](#): > > Please check the azetropes above, you can pick one that suits your need. If you are using this to treat your bows, please note that the water coming out of the wood would change the concentration and hence the boiling point. > > The other option is to use pressure control (please understand the risks of doing this). You will need about 15 psig pressure to change the water boiling temperature to 300F. Please have a relief valve in the system. > > You can also look into a silicone oil bath which stays liquid to about 360F. You can control the temperature with an electrical controller. I did plan on using this to heat treat the wood for the bows. What I had in mind was something that could be used in a remote campsite. I could use a thermometer and add water as it boiled off based on the temps I was getting. We still have a lot of experimenting to do as to what are optimum times and temps to heat treat this wood for maximum performance.