unit 15

Question 1

solutions

Answer 1

a homogeneous mixture in which the components are uniformly interminged

Question 2

Properties of Water

Answer 2

Triatomic molecule
Contains covalent bonds
Polar molecule

Question 3

Hydrogen Bonds

Answer 3

intermolecular attractions between water molecules
affects surface tension and vapor pressure
*strongest molecular force

Question 4

surface tension

Answer 4

inward force that minimizes the area of a liquid

Water molecules at the surface cannot hydrogen bond with air therefore turns inward to form a skin

Question 5

Surfactant

Answer 5

Interferes with hydrogen bonding therefore reduce surface tension

• causes water molecules to collapse
  ex: soaps/detergents

Question 6

Vapor pressure

Answer 6

pressure of the gas acting above the liquid in a sealed container
Water has low vapor pressure due to hydrogen bonds

Question 7

solid state of water

Answer 7

density decreases as water change to a solid

Honeycomb

Question 8

solvent

Answer 8

the substance present in the largest amount in a solution

*substance that does the dissolving

Question 9

solute

Answer 9

the other substance(s) in a solution

*substance that is dissolved

Question 10

solvations

Answer 10

positive and negative ions of an ionic solid become surrounded by solvent molecules

Question 11

polar solvents dissolve..

Answer 11

polar molecules and ionic compounds

Question 12

Nonpolar solvents dissolve..

Answer 12

nonpolar solutes

Question 13

Electrolytes

Answer 13

Substances that break up in water to produce ions

These ions can conduct electric currents

Question 14

Suspensions

Answer 14

large particle size ( > 1000nm) particles will settle out

will not stay suspended indefinitely

Question 15

Colloids

Answer 15

smaller particle size than suspensions but larger then solutions (1nm to 1000nm)

Question 16

Solutions (homogeneous mixture) size

Answer 16

small particle size

Question 17

Emulsion

Answer 17

Colloidal dispersion of a liquid in a liquid

Ex: egg yolk

Question 18

solubility

Answer 18

the amount of a substance that dissolves in 100g of water at a given temperature to produce a saturated solution

Question 19

“Like dissolved like”

Answer 19

polar molecules dissolve polar molecules

nonpolar molecules dissolve nonpolar molecules

Question 20

saturated

Answer 20

when a solution contains the maximum amount of solute

Question 21

unsaturated

Answer 21

when a solvent can dissolve more solute

Question 22

supersaturated

Answer 22

when the solution contains more solute than a saturated solute will hold at that temperature

Question 23

concentrated

Answer 23

when a relatively large amount of solute is dissolved

Question 24

dilute

Answer 24

when a relatively small amount of solute is dissolved

Question 25

Factors Affecting the Rate of Dissolution

Answer 25

Surface Area (particle size) Stirring (agitation) Temperature

Question 26

Molarity

Answer 26

the number of moles of solute per liters of solution M = moles of solute --------------------- liter of solution

Question 27

3 Properties of Water

Answer 27

High surface tension Low vapor pressure High boiling point

Question 28

Vapor Pressure of water

Answer 28

*Low vapor pressure Hydrogen bonds must be broken before water changes from liquid to vapor state; so, the tendency of these molecules to escape is low and evaporation is slow

Question 29

Boiling Point of water

Answer 29

*High boiling point Hydrogen bonding is more extensive in water than in other substances, making it more difficult to disrupt the attractions between water molecules; so more heat is needed to break them apart

Question 30

Water in the solid state structure

Answer 30

Structure of ice - regular open framework of water molecules in a hexagonal arrangement

Question 31

Which substances dissolve the best in water?

Answer 31

Ionic and polar covalent componds

Question 32

Aqueous Solution

Answer 32

water that contains dissolved substances

Question 33

Nonelectrolyte

Answer 33

A compound that does not conduct an electric current in either an aqueous solution or the molten state

Question 34

In a solution that contains a strong electrolyte...

Answer 34

All or nearly all of the solute exists as an ion

Question 35

A weak electrolyte...

Answer 35

conducts an electric current poorly because only a fraction of the solute in the solution exists as an ion

Question 36

Surface Tension of water

Answer 36

Water molecules within the body of the liquid form hydrogen bonds with other molecules that surround them on all sides. On the surface, an unbalanced attraction occurs so that the water molecules are only hydrogen bonded on the inside of the drop, causing an inward force.

Question 37

miscible

Answer 37

homogeneous mixture when added together | If a substance is soluble in another substance

Question 38

immiscible

Answer 38

not forming a homogeneous mixture when added together | If a substance is insoluble in another substance

Question 39

How temperature affects the solubility of .. | solids, liquids, and gases

Answer 39

solids - varies directly liquid - varies directly gas - varies inversely

Question 40

how pressure affects the solubility of solids, liquids, and gases

Answer 40

solids- little effect on solubility liquids- little effect on solubility gases- directly proportional

Question 41

Dilution Formula

Answer 41

Moles of solute = M1 * V1 = M2 * V2 M - molarity V - Volume

Question 42

Percent by Volume of solutions

Answer 42

Percent by volume = volume of solute / volume of solution | * 100%

Question 43

Percent by mass

Answer 43

mass of solute/mass of solution | * 100%

Question 44

Molality

Answer 44

moles of solute --------------------- kg of solvent

Question 45

Freezing point formula

Answer 45

freezing point = m * 1.86 degrees C/m * i m = molarity

Question 46

1 g =

Answer 46

.001 kg