Chapter 3 Flashcards
(21 cards)
POLAR MOLECULE
A molecule (water) with an uneven distribution of charges in different regions of the molecule.
POLARITY
allows water molecules to from hydrogen bonds w/ electrons
COHESION
water binding to other water
ADHESION
water sticking to other things (cell wall)
SURFACE TENSION
the measure of how difficult it is to break the surface of a liquid ( the reason animals can walk. on water)
HYDROPHILIC
substance that has affinity for water (sugar, salt)
HYRDROPHOIC
substances that do not have affinity for water (oils, metals)
HYDROCARBON
compounds of carbon and hydrogen
EVAPORATIVE COOLING
as liquid evaporates its remaining surface cools (this helps stabilize temp. in organisms and bodies of water)
HEAT OF VAPORIZATION
the heat a liquid must absorb for 1 g to be converted to gas
FLOATING ON LIQUID WATER
- water reaches it greatest density at 4 C
- ice floats in water bc hydrogen bonds in ice are more “ordered”, making ice less dense in water.
MODERATION OF TEMP. BY WATER
- water absorbs heat from warmer air and releases stored heat to be cool air
- water can absorb or release heat in large amounts with only sight changes to its own temp.
SOLUTE
substance that is dissolved
SOLVENT
the substance that is doing the dissolving
SOLUTION
liquid that is completely homogeneous mixture of substances.
AQUEOUS SOLUTION
a solution in which water is the solvent
HYDRATION SHELL
when an ionic compound is dissolved in water, each ion is surrounded by sphere of water molecules.
HYDROGEN ION (H+)
when a hydrogen atom leaves its electron behind and is transferred as a +1 proton
HYDROXIDE ION (OH-)
a molecule that has lost a proton
HYDRONIUM ION (H30+)
when a water molecule gains an extra proton
WATER PROPERTIES
- cohesive behavior “sticky”
- ability to moderate temperature
- expansion upon freezing
- versatility as a solvent ( can dissolve in things)
