Exam 3 Flashcards
6 Strong Acids
HClO4, H2SO4, HI, HBr, HCl, HNO3
6 Strong Bases
LiOH, NaOH, KOH, Ca(OH)2, Sr(OH)2, Ba(OH)2
Ka x Kb =
Kw (1x10^-14)
In binary strength of hydrogen compounds
acid strength increases with increasing electronegativity
What is a Buffer
any solution that contains both a WA or WB and its conjugate
When you add a base
its neutralized by the acid OH^- (aq) + HA^+ (aq) -> H2O(l) + A^- (aq)
Buffer Range
the pH range over which a particular acid and its conjugate base can be effective
When you add an acid
its neutralized by the H^+ (aq) + A^- (aq) -> HA (aq)
Buffer Capacity
the amount of acid or base that can be added to a buffer without causing a large change in pH
what is a acid-base titration
a basic or acidic solution of unknown concentration is reacted with an acidic or basic solution of known concentration
what is an indicator
dye whose color depends on the pH of the solution
What does it mean to standardize
to determine the concentration of a solution
what is a titration curve
a plot of pH of the solution in a Erlenmeyer flask (y-axis) vs the volume of the solution added (x-axis)
what is the equivalence point
the point in the titration where the moles of base is stoichiometrically equal to the moles of acid
what is solubility
the amount of a substance that will dissolve in a given amount of solvent
What is molar solubility (S)
the solubility in units of moles per liter (mol/L)
what is the Solubility Constant (Ksp)
the equilibrium expression for the dissolution of an ionic compound (salts) into its aqueous ions
What is the Reaction Quotient (Q)
the reaction in which an ionic compound dissolved is the product of the concentrations of the ionic components raised to their stoichiometric coefficients
what are precipitation reactions
they occur upon the mixing of two solutions when one of the cross products is insoluble
what is the common ion effect
the tendency for common ions to decrease the ionization of a weak acid or weak base or to decrease the solubility of an ionic compound
what is selective precipitation
a process involving the addition of a reagent that forms a precipitate with only one of the ions
What is a lewis acid
any substance that can receive an electron pair
what is a lewis base
any substance that can donate an electron pair
what is the first law of thermodynamics
the energy of the universe is constant
what does it mean to be spontaneous
a process occurs without the input of energy from outside the system
what are examples of spontaneous
-waterfall runs down a hill
-a lump of sugar dissolves in a cup of coffee
-at 1atm, water freezes below 0 degrees celcius and ice melts above 0 degrees celcius
-heat flows from a hot object to one that is colder
-gas expands in a evacuated light bulb
-iron exposed to oxygen and water form rust
what is non-spontaneous
a process occurs with the input of energy from outside the system
what is entropy (S)
the measure of randomness of disorder of a system
what is the second law of thermodynamics
for any spontaneous process, the entropy of the universe increases
what is the third law of thermodynamics
the entropy of a perfect crystal at absolute zero (0K) is zero
what is standard state
-gas, 1atm pressure
-liquid or solid = usually 20 degrees celcius
-substance in a solution = 1M concentration
-Q=1
