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Raising Boiling Point of Water
Name: Michelle B.
Status: student
Age: 18
Location: N/A
Country: N/A
Date: 7/20/2004
Question:
Is there anything that can raise the boiling point of
water other than antifreeze in a radiator?
Replies:
The addition of any non-volatile soluble substance increases the boiling
point of water. If the substance is also volatile too, it contributes to the
boiling point according to well known laws. You can find out as much, and as
advanced info if you do a Google search (or some other search engine) on the
topic "boiling point elevation".
Vince Calder
Michelle,
Adding salt, for example, raises the boiling point of water. This is why
many recipes call for the addition of a small amount of salt to boiling
water -- it causes the water to "cook" what you are placing in the water at
a higher temperature. The boiling point of a solution is a colligative
property (you may read more about these at
http://www.infoplease.com/ce6/sci/A0812887.html). The addition of salt not
only raises the boiling point of water, it also lowers its freezing point
(which is why people will put salt on their steps and walkways in the
winter).
Pressure is also an important factor. Water under pressure will have a
higher boiling point temperature -- a fact used by some nuclear power plants
that heat water in the reactor, but keep the water in that loop of pipes
(the "primary loop") under pressure to prevent the water from boiling (this
is why these reactors are called "Pressurized Water Reactors"). Also,
directions for cooking rice and other items that require boiling water will
specify that longer cooking times are required at higher altitudes (such as
for people living in Denver, CO). This is because the lower atmospheric
pressure at high altitudes means that water will boil at a lower temperature
there.
Regards,
Todd Clark, Office of Science
U.S. Department of Energy
Mike,
The "average" is the climatological average,
which is an average of the conditions during the
past 30 years.
David R. Cook
Atmospheric Research Section
Environmental Research Division
Argonne National Laboratory
Michelle,
Any water-soluble, non volatile substance will raise the boiling point of water.
For example: Common table salt, (and all water-soluble inorganic compounds),
sugar, honey, glycerin, propylene glycol -- a food additive -- anything that
has a relatively high boiling point and will dissolve in water.
Regards,
ProfHoff 884
Just about anything dissolved in water will raise its boiling point and
decrease the freezing point. Antifreeze is the best / safest choice for
a radiator.
Greg Bradburn
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Update: February 2012
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