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