Weird Water Properties Answer Key

1.  Frozen water or ice is quite unusual in that it _floats  liquid water.

2. Water vapor is : more buoyant than dry air
These two abnormalities make our planet habitable and its weather paterns so intricate.
"Water is an apparently simple molecule (H2O) with a highly complex character. As a gas it is one of lightest known, as a liquid it is much denser than expected and as a solid it is much lighter than expected."
from "Water Structure and Science" by Martin Chaplin.

3. Water is known as the universal ______________.
Toy for scientists... no seriously the answer is Solvent.
(Although, ice is relatively poor as a solvent and freezing water can be used to purify it.)

From Wikipedia, the free encyclopedia
The Universal Solvent may refer to:

Plus you can take a peek at this intriguing article: The most "Universal Solvent" known.  

Finally, water at higher pressures and temperatures can disolve practically anything.

4. At four degrees centigrade (4° C) water expands on Both warming and cooling
This explains why our planet is not a just a ball of ice, but as you can imagine ii makes modeling water difficult.

5.   Hot and cold water have different properties. Which of these is NOT true:
 as cold liquid water is heated
  A .  the speed of sound within it increases true, which should be the reverse
  B.  it conducts heat better true also very odd
C. gasses become less soluble true
as hot liquid water is heated:
D. it shrinks false it expands (cold water can shrink when heated see question 4)
E.  it becomes easier to compress true

"As cold liquid water is heated it shrinks, it becomes less easy to compress, its refractive index increases, the speed of sound within it increases, gases become less soluble and it is easier to heat and conducts heat better. In contrast as hot liquid water is heated it expands, it becomes easier to compress, its refractive index reduces, the speed of sound within it decreases, gases become more soluble and it is harder to heat and a poorer conductor of heat. With increasing pressure, cold water molecules move faster but hot water molecules move slower. "
again from "Water Structure and Science" by Martin Chaplin.

6.  Viscosity measures a fluid's internal flow resistance. Water flows relatively easily in comparison to olive oil.
Under 34° C , what happens to water's viscous flow as pressure increases? It:
 B. Becomes even lower than normal
Which is unusual since normally under pressure most liquids begin to act more like solids. See

7.   Heon Kang and his colleagues in South Korea ran across Warm Ice or frozen water at room temperature, serendipitously. What had they inadvertently done to crystalize water at their ambient laboratory temperature?

C. Applied a couple of million or so volts to the sample with a scanning tunneling microscope (STM).

8. In stratiform and cumulus clouds, airplanes often run into this form of water which consequently causes serious
 problems with lift.
D.  Supercooled

9. Imagine  a ice cube. Obviously, when  the temperature increases it melts. However, it is possible to liquefy water ice without changing the temperature by:
E.   Increasing the atmospheric pressure.

10. This means it is very hard to heat up. In what phase does water have the highest specific heat, twice as high as its other forms?
B. Liquid

Bonus question:
Most people have seen broken water pipes caused by subzero temperatures. So they know that water unlike most other liquids expands when frozen. How would increasing atmospheric pressure affect the ratio of the expanded  ice to original liquid form?

Freezing water  at one bar increases its volume by aproximately 9 percent. However, counter intuitively, when  the pressure is increased, say to 200 MPa and hence lowering the freezing temperature to -20 C, water then expands  by  almost 17% in solidifying.

Ask your students if this following statement is true or what they think about it.

"All the water that will ever be is, right now."
                                        "National Geographic, October 1993

Some water demostrations
The atraction of water molecules
Needed: ping pong balls
Place two dry ping pong balls next to each other. Move one ball away. The other ball will remain in place.
Next , wet the balls repeat experiment. The balls should move in tandem.
 Static charge and ionized water.
Needed: balloon and a wter tap or faucet.
Turn on a small stream of water in the sink. Bring the balloon near. Nothing should happen. Now charge the balloon with say the hair on your head. Repeat. Note:If you use distilled water you should see no difference from the charged nd uncharged balloon
Water is diamagnetic
Needed:a petri dish & stand, small laser, water and a very strong magnet. Aim the laser  at very oblique angle at the water suface so that it almost skims the water. Place the magnet under the dish. Normally, this should change the surface of the water and thus the trajectory of the laser beam. Becareful to avoid vibrations and hence waves.
 Melting ice on the water level in a glass.
Needed: Water glass, water and ice.
 no mater how many times I see this simple demonstration I am always amazed at the result. First half fill a glass of water, add some floating ice, draw a line at the water level. Wait till the ice has melted. You may  ask the class where they think the water level will be when the

Feel free to contact me