Download Name Date Period ______ The Unique and Unusual Properties of

Name ____________________________________________ Date ________________ Period _______
The Unique and Unusual Properties of Water
Charles Riley, Jr. PE
Reading for 10.1 - 10.4: Intermolecular Forces
1.
(a) Why does the polar nature of water make it an excellent solvent?
(b) Compare water's ability to dissolve to that of other solvents.
(c) How many elements are able to dissolve in water?
(d) List 4 things on which water's ability to dissolve a substance depend:
(e) Which types of compounds tend to be difficult to dissolve in water? Given an example of this
type of compound.
2.
(a) What is surface tension and why is it important?
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2. Continued:
(b) What is special about water's surface tension?
(c) Generically, which types of compounds tend to have higher surface tensions and which tend to
have lower surface tensions?
(d) To what is the exceptionally high surface tension of water attributable?
(e) Why do drops of water form spheres?
(f) Why can object that are heavier than water "float" on water?
3.
(a) What does it mean for something to be "hydrophilic"?
(b) What does it mean for something to be "hydrophobic"?
(c) List some examples of substances which are "hydrophobic".
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3. Continued:
(d) What is the purpose of a "wetting agent"?
(e) What does it mean to "wet" a substance?
4.
(a) What is "capillary action"?
(b) List some examples that make the phenomenon of "capillary action" important.
5.
(a) List 2 reasons why is water important to biochemical processes.
(b) Explain water's role in photosynthesis.
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5. Continued:
(c) List 2 reasons why photosynthesis is so important.
6.
(a) What is the "valence" of an element?
(b) What would be the sign of the valence of an element that makes a cation? an anion? for
inorganic compounds?
(c) Do atoms with a (+) valence gain or lose electrons? with a (-) valence?
(d) What is the significance of valence in the formation of compounds?
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7. Define the term "ionic bonding" according to the article we are reading.
8.
(a) What type of bond hold together the hydrogen and oxygen atoms in a water molecule?
(b) How is the distribution of the electrons in the bonds of water different from the distribution of
electrons in the bonds of sodium chloride?
9.
(a) In the water molecule, which atom exerts a stronger pull on the shared electrons? How does this
affect the electronegativity both the oxygen and hydrogen atoms?
(b) Why does the distribution of the (+) and (-) regions make the water molecule polar?
(c) How does the polar nature of the water molecule make it behave towards other water molecules
and ions?
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9. Continued:
(d) What "parts" of separate water molecules are attracted to each other? What is this "bridging"
phenomenon called?
10.
(a) Hydrogen bonding is responsible for what percentage of the strength of a covalent bond?
(b) List 7 physical phenomenon of water for which hydrogen bonding is responsible.
(c) Explain a chemical phenomenon for which hydrogen bonding is responsible.
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10. Continued:
(d) Why is pure water a relatively poor conductor of electricity?
(e) Explain the principle that allows water's purity to measured with a conductivity or resistivity
meter.
11.
(a) Explain hydrogen bonding's role in the relative density of ice and water.
(b) What happens to the melting point of water when pressure is increased on ice? How do you
think this affect the hydrogen bonds of ice?
12.
(a) How does a water molecule align itself in an electric field?
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12. Continue:
(b) What is a "dipole moment" according to the article? What do you think this means "in English"
in terms of chemical bonds?
(c) How does water's dipole moment compare with that of other inorganic compounds?
(d) How is the dipole moment of water responsible for its ability to dissolve a wide variety of
substances?
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