Chapter 3 Biology
The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?
hydrogen bond
What gives rise to the cohesiveness of water molecules?
hydrogen bonds
What type of bond must be broken for water to vaporize?
hydrogen bonds (between water molecules)
Why does ice float in liquid water?
hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water
What takes place as an ice cube cools a drink?
kinetic energy in the drink decreases
Hydrophobic substances such as vegetable oil are?
nonpolar substances that repel water molecules
What is an example of a hydrogen bond
the H of one water molecule and the O of another water molecule
Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?
the absorption of heat by the breaking of hydrogen bonds
What defines a kilocalorie?
the amount of heat required to raise the temperature of 1 kg of water by 1 degree Celsius
Why is water able to form hydrogen bonds?
the bonds that hold together the atoms in a water molecule are polar covalent bonds
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by what kind of bond?
Polar covalent bonds
What effect is produced by the high surface tension of water?
a water strider can walk across the surface of a small pond
Water's high specific heat is mainly a consequence of what?
absorption and release of heat when hydrogen bonds break and form
Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this?
the release of heat by the formation of hydrogen bonds