CHEM 1040 - Final Exam Auburn University

dipole-dipole

attractive forces between POLAR molecules

hydrogen bonding

special type of dipole-dipole that occurs between molecules that contain an H bonded to N, O, or F

dispersion forces

attractive forces from an instantaneous dipole

surface tension

amount of energy required to stretch the surface of a liquid by 1 unit area

capillary action

movement of a liquid up a narrow tube

viscosity

measure of a fluids resistance to flow

(> IMF = > viscosity)

vapor pressure

amount of energy that the liquid is pushing on the gas above its surface

( > VP = > vaporization)

boiling point

temperature at which vapor pressure equals the external atmospheric pressure

melting point

temperature at which the energies of individual particles enable them to break free of their fixed positions in the solid

critical temperature

the temp above which a gas cannot be liquified no matter the pressure

heat capacity

the number of heat units needed to raise the temperature of a substance by 1 degree celsius

fusion

melting

supercooling

when a liquid is cooled below its freezing point

sublimation

the process by which molecules go directly from the SOLID phase to the GAS phase

deposition

the process by which molecules go directly from the GAS phase to the SOLID phase

phase diagrams

saturated solution

contains the maximum solute particles that can be dissolved into a solvent at a specific temperature

entropy

a measure of how spread out energy is

(gas > liquid > solid)

molarity

mols solute / liters sln

mole fraction

mols of A / total mols

molality

mols solute / kg solvent

percent by mass

(mass solute / total mass) x 100

colligative properties

depend on the number of solute particles in solution but do not depend on the nature of the particles

the colligative properties are:

vapor pressure lowering

boiling point elevation

freezing point depression

osmotic pressure

van't hoff factor (i)

accounts for effect of the number of particles in solution

actual # particles in sln / # formula units initially dissolved

van't hoff factor of non-electrolytes

1

van't hoff factor for strong electrolytes (NaCl, KOH, KBr, HNO3, etc.)

equal to the number of ions

spontaneous process

a process that DOES occur under a specific set of conditions

non-spontaneous process

a process that does NOT occur under a specific set of conditions

process that result in a decrease in energy in a system are often ________________________.

spontaneous

spontaneity is favored by an ________________ in a system's entropy.

increase

in addition to translational motion, molecules exhibit _____________ and ______________.

rotations , vibrations

several process that lead to an increase in entropy include:

melting

vaporization or sublimation

temperature increase

reaction resulting in > # of gas molecules

second law of thermodynamics

for a process to be spontaneous, deltaS of the universe must be positive

third law of thermodynamics

the entropy of a perfect crystalline substance is zero at 0 K (absolute zero)

gibbs free energy

helps express spontaneity

standard free energy of reaction

free-energy change for a reaction when it occurs under standard state conditions

equilibrium

when the rates of the forward reaction and the reverse reaction are EQUAL

reaction quotient

law of mass action

equilibrium constant (Kc) equal reaction quotient (Qc) at equilibrium

LARGE Kc

products favored

SMALL Kc

reactant favored

only ______________ and ________________ species appear in equilibrium expressions.

gaseous , aqueous

(do NOT include pure liquids and solids)

when an equilibrium expression contains only gases, we can write an alternate form in which the concentrations are expressed as _________________.

partial pressures

(Kp)

K >> 1

negative deltaG^o

K << 1

postive deltaG^o

Q < K

reaction proceeds to the right

(reactants to products)

Q = K

system is at equilibrium

Q > K

reaction proceeds to the left

(products to reactants)

deltaG determines _______________.

spontaneity

le chatelier's principle

when a STRESS is applied to a system at equilibrium, the system will respond by SHIFTING in the direction that minimizes the stress

le chatelier's principle

STRESSES:

addition of reactant/product

removal of reactant/product

change in volume

change in temperature

bronsted acid

donates proton

bronsted base

accepts proton

hydrohalic acids

HF << HCl < HBr < HI

oxoacids

contains H, O, and central nonmetal

carboxylic acids

amphoteric

a species that can behave as either an acid or a base

auto-ionization of water

Kw

strong acids

HCl

HBr

HI

HNO3

HClO3

HClO4

H2SO4

strong bases

LiOH

NaOH

KOH

RbOH

CsOH

Ca(OH)2

Sr(OH)2

Ba(OH)2

salt hydrolysis

occurs when ions produced by the dissociation of a salt react with water to produce either hydroxide ions or hydronium ions

basic salts

conjugates of weak acids

acidic salts

conjugates of weak bases

a cation that will make a solution ACIDIC

conjugate of a weak base

small highly charged metal (not 1A or 2A)

an anion that will make a solution BASIC

the conjugate base of a weak acid

cation that DOES NOT effect pH

a group 1A or heavy 2A

anion that DOES NOT effect pH

conjugate base of a strong acid

buffer

a solution that contains a weak acid/base and its conjugate base/acid

henderson hasselbach equation

for BUFFERS

buffer concentrations

must have conjugate acid and base concentrations within a factor of 10

the pH of a buffer cannot be more than ______ pH unit different than the _____ of the weak acid it contains.

1 , pKa

pKa

-logKa

equivalence point

# moles acid = # moles base

pH = pKa when ________

[A-] = [HA]

at the half equivalence point

solubility product constant (Ksp)

gives a quantitative prediction about how much of a given ionic compound will dissolve in water

molar solubility

# moles of solute in 1 L of a saturated solution (mol/L)

solubility

the # grams of solute in 1 L of a saturated solution (g/L)

Q = Ksp

Q < Ksp

no precipitate

Q > Ksp

precipitate forms

factors that affect the solubility of ionic compounds

common ion effect

pH

formation of complex ions

complex ion

an ion containing a central metal cation bonded to one or more molecules or ions

fractional precipitation

the separation of mixtures based on the compounds solubilities

qualitative analysis

uses selective precipitation to identify the types of ions present in solution

redox reaction

a reaction in which there are changes in oxidation states

galvanic cell

experimental apparatus for GENERATING electricity through a SPONTANEOUS reaction

(current flows from anode to cathode)

Ecell =

under non-standard conditions, cell potential is calculated with the NERNST EQUATION

concentration cell

2 half-cells containing the same components but differing ion concentrations

dry cell batteries

no fluid components

zinc container (anode)

graphite cathode

1.5 V

alkaline batteries

basic medium

lead storage batteries

6 cells

2 V per cell

12 V total

rechargeable

(CARS)

lithium ion batteries

cell potential 3.4 V

rechargeable (many times)

(PHONES, other electronics)

fuel cells

cell potential 1.23 V

~70% efficient

electrolysis

the use of an electric cell to drive a non-spontaneous reaction

electrolytic cell

non-spontaneous

electrical energy is consumed

corrosion

generally refers to the deterioration of a metal by an electrochemical process

kinematics

study of how fast reactions take place

collision theory

the reaction rate is directly proportional to the number of molecular collisions per second