Chem Exam 1

The sum of all the mole fractions must equal what?

1

Normal melting or freezing occurs at P =

1 atm

A liquid boils when the vapor P = _________ Pushing up = Pushing down

Atmospheric P

Ice will float on surface of water Layer of ice on top protects water underneath from being to cold

Density

The reverse process: (g) -> (s)

Deposition

If solute and solvent intermolecular forces are ______ the pair will be insoluble

Dissimilar

Solvent-solute interactions determine if a substance will ________ in a particular solvent

Dissolve

Solvent vapor pressure ______ if non-volatile solute is added

Drops

Heat added break bonds

Endothermic Process

Quantity of thermal energy transferred into/out of a system at constant pressure

Enthalpy Change

E released as an ion becomes hydrated

Enthalpy of Hydration

Amount of energy or heat needed to have a transition of liquid to gas

Enthalpy of Vaporization

Heat released make bonds

Exothermic Process

Products ______ with time. Positive sign

Increase

Non-volatile solutes ______ the boiling point of a solvent Why?

Increase Solvent vapor P is lowered Higher T is needed to get the vapor P = external P

Solubility of solids usually ______ as temperature increases

Increases

Lattice points occupied by cations and anions Held together by electrostatic attraction Hard, brittle, high melting point Poor conductor of heat and electricity

Ionic Crystals of Solids

When an ________ compound dissolves in water, the _____ overcome the forces holding them in the lattice. Become hydrated (surrounded by water).

Ionic Ions

No net flow

Isotonic

A cell can be exposed to what 3 kinds of solutions?

Isotonic Hypertonic Hypotonic

E required to overcome the forces holding the ions together in a crystal

Lattice Energy

Has it's own volume and takes the shape of the container Translational motion, faster Particles are arranged more randomly than a solid Slightly compressible Intermolecular interactions

Liquid

Solutes lower vapor pressure and extend the T-range over which a solvent remains _____

Liquid

Non-volatile solute _______ the freezing point of a solvent

Lowers

Heat required to ______ 1 mol (P= 1 bar)

Melt

What are the factors that affect the speed of all reactions?

Properties Concentrations Temperature Catalysts

Miscible liquids dissolve in all _______

Proportions

P1=X1P1

Raoluts Law

The ____ is directly proportional to OH-

Rate

When OH- is doubled the _____ doubles

Rate

Calculus is used to integrate a ____ _____

Rate Law

______ _____ must be measured. They cannot be predicted from reaction stoichiometry

Rate Laws

Chemical kinetics is also called _______ kinetics

Reaction

Flow is reversed if P > pi is applied Pure water can be separated from brine

Reverse Osmosis

No more solute will dissolve Undissolved solid is often present

Saturated Solution

Immiscible liquids form distinct ________ _______

Separate phases

If solute and solvent intermolecular forces are _______ the pair will be soluble

Similar

Fixed volume and shape Particles vibrate around fixed positions (Brownian Motion) Incompressible Ordered External Shape often reflects internal arrangement of particles

Solid

All other components (may be >1)

Solute

The molality, m depends on the ______

Solute

Homogeneous mixture of substances. Exist in all 3 physical states Can be mixtures of solids, liquids and gases

Solution

Solute constantly moves in and out of ______

Solution

Component in the greatest amount

Solvent

Kf is a constant for the _______

Solvent

The Kb value only depends on the _______

Solvent

What 2 things do solutions consist of?

Solvent Solute

Highest of all liquids and solids except NH3 Moderates T in the environment and in organisms; climate affected by movement

Specific Heat Capacity

Osmotic pressure = Pthat must be applied to _____ osmosis

Stop

The direct conversion of a solid to a gas

Sublimation

When a solution is __________ it has more solute dissolved than would occur under normal conditions

Supersaturated

Have more than the equilibrium amount dissolved

Supersaturated Solution

Heterogeneous reaction rates may also depend upon _____ _____

Surface Area

Highest of all molecular liquids Contributes to capillary action in plants causes formation of spherical droplets, supports insects on water surfaces

Surface Tension

Surface-active agents have a hydrophobic and a hydrophilic part. Soaps and detergents Common soap is odium stearate Dissociates in water to give Na+ Soap = fatty acid salt Detergents are similar, but use other polar head groups

Surfactants

Basic repeating structural unit of a crystalline

Unit Cell

____ is the Van't Hoff factor (indicates the number of chunks the solute dissociates into)

i

Reactants ______ with time. Negative sign.

Decrease

Gas solubility almost always _______ as temperature increases

Decreases

Liquids boil when their vapor P = atmospheric P (______ mmHg)

760

Normal boiling point is at 100 C?

760 atm

The normal bp occurs at 1 atm =

760 mmHg

Does not possess a well defined arrangement and long range molecular order

Amorphous Solid

______ occurs when the VP of a substance = air pressure above the liquid Decreases with increasing VP (diff. substances at the same temperature) Increases with increasing intermolecular forces Increases with increasing atmospheric pressure Increases with addition of a non-volatile solute

Boiling

Bubbles (vapor) of liquid form in _____ ______. (not air)

Bulk Liquid

The study of speeds of reactions and the nanoscale pathways or rearrangements by which atoms and molecules are transformed from reactants to products.

Chemical Kinetics

Vapor pressure lowering, boiling pressure elevation, and freezing point depression are _______ properties

Colligative

Ions attract each other in solution Only act as separate units at very low (ion) i is smaller than expected in many solutions

Colligative Properties of Electrolytes

Large particles (dispersed phase) uniformly distributed through a solvent-like medium (continuous phase) Look homogeneous, but a microscope shows they are not 10 - 1000x bigger than single molecules Smaller than particles in suspensions

Colloids

The reverse process is exothermic

Condensation

The end of the liquid/gas equilibrium line. It occurs at the critical temperature, T and critical pressure P

Critical Point

Possesses rigid and long range order

Crystalline Solid

Solidification, crystallization is exothermic

Freezing

Has the volume and the shape of the container Particles are not arranged in order Particles in continuous, random, rapid motion Compressible Particles do not interact much with one another

Gas

8.314 J/mol K

Gas constant

Solution Air

Gas in gas

______ ______ stays constant for first order, always equivalent to .693/k

Half Life

Contains relatively high concentrations of Ca2+, Mg2+, Fe3+, and MN2+ ions May give a nasty taste to water

Hard Water

Highest of all molecular solids except NH3 Freezing water releases large quantity of thermal E; used to save crops from freezing by spraying them with liquid water

Heat of Fusion

Highest of all molecular substances Condensation of water vapor in clouds releases large quantities of thermal E fueling storms

Heat of Vaporization

Gas solubility is directly proportional to pressure of the gas

Henrys Law

Sg=KhPg

Henrys Law

Species in multiple phases

Heterogeneous

Reactants and products in one phase

Homogeneous

Reactions are either ______ or ______

Homogeneous Heterogeneous

Net flow out

Hypertonic

Net flow in

Hypotonic

Sperical colloid of surfactant molecules. If soap is added to water, the surfactants: Form spheres with - polar heads (hydrophilic) pointing out (into water) and non-poloar tails (hydrophobic pointing in The hydrophobic center encapsulates oil and grease Oils and greases become water soluble

Micelles

m is ______

Molality

Lattice points occupied by molecule Held together by intermolecular forces Soft, low melting point Poor conductor of heat and electricity

Molecular Crystals or Solids

Lattice points occupied by atoms Held together by covalent bonds Hard, ugh melting point Poor conductor of heat and electricity

Network or Covalent Crystals or Solids

Water molecules cross the membrane diluting the brine. Flow stops when P = pi is applied

Normal Osmosis

Allows passage of small "particles". Stops large "particles" Animal bladders and cell membranes Movement of solvent through a semipermeable membrane from dilute to more concentrated solution

Osmotic Pressure

pi=cRTi

Osmotic Pressure

Highest of all molecular liquids Aids heat transfer in organisms rapidly cools organisms immersed in cold water, causing hypothermia

Thermal Conductivity

All added solid is dissolved Can dissolve more solute

Unsaturated Solution

Increases with increasing temperature Decreases with increasing intermolecular forces Decreases with addition of a non-volatile solute

Vapor Pressure