Analyze Water Properties. Name:
1. How does the colored water get into the leaves?
Through capillary action. Adhesion & Cohesion.
2. What properties of water allow for this to happen?
Adhesion (attracted to other polar molecules) & cohesion
(attracted to itself)
3. Why is this important for life?
Plants give off oxygen, but need water to live. Without
living plants we could not live as we need the oxygen
they give off. So, getting water to the leaves, where
photosynthesis and oxygen production takes place, is
vitally important to all organisms that need oxygen.
4. Why doesn’t oil & water mix?
Water is polar, but oil is non-polar & inherently hydrophobic.
Being hydrophobic causes oil to run away, so to speak, from
water.
5. What property of water creates this scenario?
Basically, water being polar causes this to happen.
6. Why is this important for life?
Membranes surround all cells and their properties are very important to how our
biological systems work. Since they are repelled by water,
they are forced to spontaneously form in our water-based
bodies.
7. What property allows water to bead up?
Cohesion & surface tension.
8. Why is this important for life?
Ultimately, surface tension relates to the cohesive properties of water.
This is important because it keeps water in fluid form rather than
evaporating into the atmosphere.
9. Why can water dissolve so many particles?
Because it’s polar. The polar interactions from water with other polar
molecules interferes with the solute’s cohesive properties (the attraction
to itself that keeps it held together). This breaks the solute down and
causes it to be dispersed in the water evenly… dissolved.
10. What property allows water to do this?
The polarity of water allows is to be an effective solvent.
11. Why is this important for life?
Chemical reactions are much more likely to be completed in aqueous (fluid, specifically water-based) solutions.
Considering life is literally a series of complex chemical reactions, life has taken hold and persists best when
water is involved.
12. Water will bead up on wax paper but spread out on
glass. Explain this.
Wax is a lipid, so non-polar. Water doesn’t interact well
with non-polar substances so is more likely to interact with
itself through cohesion. Glass, on the other hand, is
slightly polar so water will interact with itself to an extent,
but more with the glass, spreading out in the process.
13. Why does water resist vaporization?
Vaporization is caused when molecules in a fluid absorb enough energy to escape the cohesive bonds
(hydrogen bonds) that hold in suspension. There are many hydrogen bonds in fluid water that are stronger
than the energy absorbed that would otherwise energize the molecules, sending it into the vapor state.
14. Why is this important for life?
This property keeps water more likely in its fluid state, maintaining more water in fluid form making it available
to be a medium for chemical reactions that support life.
15. How does water react to changes in temperature? Does water heat up quickly or slowly?
Due to water’s high capacity to absorb heat and dissipate this in its hydrogen bonds, water resists boiling more
than most fluid.
16. Why is this important for life?
This helps organisms maintain homeostasis, resisting temperature changes that would otherwise disrupt the
natural efficiency of molecules of enzymes, which are temperature-dependent.
17. Draw 10 water molecules, properly oriented, hydrogen bonded to one another.
Either using space-filling models (shown left) or structural
formulas (right), hydrogen bonds are represented by
dashed lines spanning the distance between the negative
pole of the oxygen to the positive pole of hydrogen.
18. Some adult insects are unable to swim but are able to walk on top of water. What characteristic of
water enables these insects to walk on top of water?
A. pH
C. atomic bonds
B. solvent properties
D. surface tension
19. Which term refers to water’s attraction to other substances that have full or partial electrical charges?
A. polarity
D. solvent
B. adhesion
E. density
C. cohesion
20. Which term refers to water having partial positive charges and a partial negative charge?
A. cohesion
D. good solvent
B. surface tension
E. adhesion
C. polarity
21. Which term refers to water’s attraction to different substances?
A. polarity
D. good solvent
B. cohesion
E. adhesion
C. surface tension
22. Which term refers to the fact that water can dissolve polar molecules like sugar or ionic substances like
salt?
A. surface tension
C. polarity
B. high heat capacity
D. cohesion
23. Which part(s) of a water molecule has/have a partial positive charge?
A. the two hydrogen (H) atoms
C. the one hydrogen (H) atom
B. the two oxygen (O) atoms
D. the one oxygen (O) atom
24. Which characteristic of water allows a paperclip to remain “floating” on water when the paperclip is
gently placed on top of the water (even though paperclips are denser than water)?
A. adhesion
D. nonpolar
B. surface tension
E. inorganic
C. solvent properties
25. Plants need to move water from their roots to their leaves in order to perform photosynthesis. The tube
system that moves the water is called xylem. What property of water allows water to move up the xylem
into the leaves?
A. Evaporation
C. Specific Heat
B. Three phases of water, solid, liquid, or
D. Capillary Action
gas
26. Water has a high specific heat capacity; this means that it takes a lot of energy to change the
temperature of water. Which of the following explains why this is important to life?
a. Allow water to boil faster than other substance such as oil.
b. Helps organisms to maintain a constant internal temperature.
c. Helps organisms maintain an osmotic balance.
d. Helps organisms transport substance throughout the organisms.