Why is salt thrown on the frozen road ?

Answer Posted / guest

One unique propety of water is that its solid form is less
dense than its liquid form. This is why ice floats and
also why lakes don't freeze from the bottom up. In the
liquid form, water molecules at any given moment react with
an average of 3.6 other molecules of water. As liquid
water cools it becomes most dense at 4C. When it reaches
its freezing point at 0C, the molecules arrange themselves
so that they are reacting with exactly 4 other molecules of
water, expansion.
When salt(NaCl) is added to water it separates into Na+ and
Cl- and the water molecules form a hydration shell around
them. Now, when water reaches its freezing point, its
regular ice structure is disrupted by the presense of these
hydration shells around Na+ and Cl-. This effect is best
demonstated by icebergs. The ice forms a jagged structure
mostly underwater. Water normally freezes in sheets.
The salt is not actually lowering waters freezing point,
water is still chemically the same. The salt is just
disrupting ice formation (hypothetical-it will still take
lower temperatures to have noticable ice formation). You
will have better driving conditons when the roads do turn
icy. You won't have a slick layer of ice anymore...for a
period of time at least.

Is This Answer Correct ?    6 Yes 1 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

How is librated iodine estimated?

614


What is density of a liquid?

587


can we Consider the Purity threshold and Purity angle in place of peak purity for the specificity test for method verification

1312


What is the principle involved in conductometric titration?

629


What is mineral water?

616






What is the resulting solution when benzene and toluene are mixed ?

580


How many electrons does benzene have?

581


Why is mercuric chloride added?

635


Explain the process of spontaneous combustion?

590


What is the function of diethyl amine?

629


Why graphite rod is used in nuclear reactor?

607


Define what is avogadro’s law?

604


How does the viscosity vary with temperature?

588


What is the min constitutes of haematite ore?

568


Differentiate between organic and inorganic chemistry?

594