# Raising boiling point of salt water

How much salt per quart does it take to raise the temperature of water to 325 degrees at 28 PSI?

I am sorry to say I am not educated in physics but I do understand the more particles in the water the higher the boiling point. I am trying to plasticize animal horns in a pressure cooker with a maximum pressure of 28 psi.

Thank you for making this kitchen table ready !

Shalom

Shofarsogood

## Answers and Replies

Related Classical Physics News on Phys.org
alxm
Science Advisor
Answer: No amount. Look at a Dühring plot; saturating water with NaCl only raises its boiling point by about 10 degrees C. You can't get up to 325 F without pressures substantially larger than 28 psi.

Then there's also a quite obvious concern about having highly pressurized boiling water around, and using pressure cookers in ways they're not intended.

Why not just use oil instead?

Thanks, for the prompt reply. The dilema is not to cook the horn by using direct heat. I am concerned about the horn becoming brittle. I know it is possible to soften the solid tip deep enough to straighten it sufficiently to drill and form a mouthpiece.

The particular pressure cooker I am using has two saftey devices integral to keep it safe. One is set at 28 lbs PSI, the other is at 40 PSI, (and is not mechanical but a failure point of a rubber plug in case the first fails). The tank itself can go much higher, well over 100 psi without failure. I contacted the design department first to make sure I was not in danger.

Not sure if food safe glycerin would work?

Are there other ways to create moist heat above 300 degrees? I thought about super heating steam.

Any help would be appreciated. The horn is keratin much like a tough fingernail.

Thanks

alxm
Science Advisor
Not sure if food safe glycerin would work?
That'd work. It's got a boiling point well over 300 (554 F). If you must have some water in it, you could add about 5-10% water (by weight) and get a boiling point at about 300 degrees at atmospheric pressure, according to http://www.dow.com/glycerine/resources/table16_91100.htm" [Broken]. Should be fairly easy to test yourself, on a stove with a thermometer.

Are there other ways to create moist heat above 300 degrees? I thought about super heating steam.
Yeah well that's what you'd need with just water or water/salt. Most autoclaves don't go that high even (and if you've seen one, they're a lot sturdier than a pressure cooker.) I'd strongly recommend against working at elevated pressures. Worst case scenario doing it the first way is a spill, worst case the latter way means an explosion.

Last edited by a moderator: