Chemistry

A water molecule is a simple_____molecule and it is also_____.
triatomic; polar
What prevents most liquid water molecules from escaping the surface of the liquid?
hydrogen bonding
What are five properties of the water molecule?
high surface tension, low vapor pressure, high specific heat capacity, high heat of vaporization, and high boiling point
Water surface acts as a _____.
skin-surface tension
The inward force that minimizes surface area of a liquid is called_____.
surface tension
Surface tesnion holds water in a _____shape.
spherical
How can surface tension be decreased? What does this interfere with?
by adding surfactant; hydrogen bonding
What is vapor pressure caused by?
molecules escaping liquid
What type of systems are heterogeneous mixtures? what types are homogeneous?
colloids and suspensions; solutions
In a suspension, are the particles bigger or smaller than the particles in a solution?
bigger
How does the size of teh particles in colloids compare to those of suspensions and true solutions?
they are intermediate in size
The dispersion can be____,_____,or____.
solid, liquid, or gas
What are two examples of a colloid?
smoke and glue
When concentrated, colloids can appear_____or_____. When very dilute they are almost_____.
milky or cloudy; clear
What is the tyndall effect?
the scattering of visible light in all directions
What two types of systems exhibit the tyndall effect?
colloids and suspensions
What is the brownian motion?
chatoic movement of colloidal particles
What causes the brownian motion?
the collisions of the water molecules of the medium with the small, dispersed colloidal particles
All the particles in a particular colloidal system have the same_____.
charge
What must happen to hydrogen bonds before water changes from liquid to vapor?
they must be broken
What does water’s high heat of vaporization help to accomplish?
helps moderate temperature in the tropic and polar regions
As water cools does it become more or less dense?
more
Below 4 degrees celsius, water becomes more or less dense?
less
Why does ice float?
becasue ice is less dense than liquid water at zero degress celsius
What structure do the water molecules in ice make?
;a honeycomb
Which is more closely packed: ice or liquid water?
liquid water
Because ice floats, ice _____water below it and it keeps water at the bottom above what temperature?
insultates; zero degrees celsius
What is an aqueous solution?
water containing dissolved substances
What is the solvent? What is the sollute?
dissolving medium; dissolved particles
Solute particles can be ____or_____.
ionic or molecular
_____is the process that occurs when a solute dissolves.
solvation
What surrounds the solute particles?
solvent molecules
______are compounds that conduct electric current in aqueous solutions or in the molten state.
electrolytes
______are compounds that do no conduct electric current in aqueous solution or the molten state.
nonelectrolytes
_____is a solution in which only a fraction of the solute exists as ions.
weak electrolyte
______is when almost all the solute exists as separate ions.
strong electrolyte
What is water of hydration?
when water is chemically combined in crysal
What is a hydrate?
compound that contains water of hydration
What happens to a hydrate when it’s heated?
it loses the water
Are the forces holding the water molecules in together in hydrate strong or not strong?
not strong
What does it mean when a hydrate effloresces?
it loses water to the air
What does it mean when a hydrate is hygroscopic?
compounds remove moisture from the air
What is a synonym for hygroscopic?
desiccants
What does it mean when a hydrate is deliquescent?
compounds absorb so much water from the air that they dissolve completely and form solutions
_____are electrolytes when melted or dissoled in water.
ionic compounds
Do solutions exhibit the tyndall effect?
no
Do particles in a colloid settle out over time?
no
Will ethanol, a polar comound dissolve in water?
yes
The attractions between adjacent water molecules are called_____.
hydrogen bonds
The attractions between adjacent water atoms are called ______.
covalent bonds
What two types of systems exhibit the tyndall effect?
colloids and suspensions
Non polar compounds dissolve in _____.
nonpolar solvents
What types of cpounds dissolve in water?
polar compounds because water is polar
What type of compounds are polar? What types are nonpolar?
ionic are polar; molecular are nonpolar