223z_midterm1
Terms in this set (108)
list of strong acids (6)
HNO3 < H2SO4 < HCl < HBr < HI < HCLO4
list of strong bases (6)
LiOH < NaOH < KOH < Sr(OH)2 < Ca(OH)2 < Ba(OH)2
(𝛂) more stable base resonance structure
(𝛂) stronger acid
(𝛃) larger atoms (down a group)
(𝛃) stronger acid
(𝛄) electronegative surroundings
(𝛄) stronger acid
group 2 hydroxide
release 2 OH-, more base per mole
larger ions
separate more easily
more soluble
stronger base
arrhenius acid
substance that produces H+ ions
arrhenius base
substance that produces OH- ions
electrolyte (acid/base)
substance that forms ions in solution
electrolyte strength
depends on extent of dissociation
strong acid/base
complete dissociation
weak acid/base
partial dissociation
brønsted-lowry acid
proton (H+) donor
brønsted-lowry base
proton (H+) acceptor
amphoteric substance
can act as an acid or a base
conjugate acid-base pair
2 substances related by the transfer of a proton
conjugate acid
a base with a proton added to it
conjugate base
an acid with a proton removed from it
binary acid
H-Y
oxyacids
H-O-Y
acidic H-Y bond
H atom has positive dipole moment
increasing acidity
decreasing bond strength
affects H-O-Y strength (2)
electronegativity of Y
number of O atoms bonded to Y
far right equilibrium
complete ionization
monoprotic acid
only 1 ionizable proton
hydrofluoric acid
HF (weak)
acetic acid
HC2H3O2 (weak)
formic acid
HCHO2 (weak)
sulfurous acid
H2SO3 (weak)
carbonic acid
H2CO3 (weak)
phosphoric acid
H3PO4 (weak)
acid ionization constant (Ka)
quantifies acid strength
smaller Ka
less ionization in water
pKa
-log(Ka)
autoionization
water acts as an acid/base with itself
ion product constant (Kw)
[H3O+] x [OH-] = 1.0 x 10^-14
acidic solution
[H3O+] > [OH-]
basic solution
[H3O+] < [OH-]
pH
-log[H3O+]
pH scale [H+]
decreases by a factor of 10
smaller pKa
stronger acid
Ka
[HA] [A-] / [HA]
% ionization of a weak acid
[H3O+] at equilibrium divided by initial [HA]
with increasing [HA] initial (2)
[H3O+]eq increases
% ionization decreases
[H3O+] for a mix of acids
[strong acid] = total [H3O+]
most weak bases
act as a base by accepting a proton from water
most strong bases
group 1A and 2A metal hydroxides
group 2A: M(OH)2
dissociates in a single step
amines (most weak bases)
ammonia with 1+ hydrocarbon groups substituted for 1+ hydrogen atoms, have a nitrogen atom w/ a lone pair acting as a proton acceptor
anions
form basic or neutral solutions
cations
form acidic or neutral solutions
anion that's a conj. base of a weak acid
weak base
anion that's a conj. base of a strong acid
pH neutral
Kb of an anion
use Ka of its conj. acid
(cation) counterions of strong bases
pH neutral
(cation) conj. acids of weak bases
weakly acidic
(cation) small highly charged metals
weakly acidic
(salts) cation/anion doesn't act as an acid/base
neutral solution
(salts) anion acts as a base
basic solution
(salts) cation acts as an acid
acidic solution
(salts) cation/anion acts as an acid/base
ion with the higher K determines pH
polyprotic acids
ionizes in successive steps, Ka1 > Ka2
lewis acid
electron pair acceptor (has an incomplete octet)
lewis base
electron pair donor
adduct
product of a lewis acid/base reaction
conj. acid of a weak base (low tendency to accept protons)
high tendency to donate protons
hydrolysis
ion reacts with water to form H+ or OH-
conj. base of a weak acid
produces OH-
conj. acid of a weak base
produces H3O+
small, highly charged metal cations
produces H3O+
conjugates of strong acids
neutral pH
conjugates of strong bases
neutral pH
a buffer is made of
significant amounts of a weak acid and its conjugate base
a buffer resists pH by
neutralizing the added acid/base
strong base added to buffer
neutralized by weak acid
strong acid added to buffer
neutralized by conj. base
common ion effect
a solution with 2 substances that a share common ion decreases the amount of ionization in a weak acid/base
[H3O+] = Ka
in a solution with equal acid and conj. base concentrations
henderson-hasselbalch equation
pH = pKa + log([base]/[acid])
acid added to buffer
stoich. amount of weak base is converted to conj. acid
base added to buffer
stoich. amount of weak acid is converted to conj. base
effectiveness of a buffer depends on (2)
relative amounts of acid/base
absolute concentrations of acid/base
capacity of a buffer
how much acid/base it can neutralize
range of a buffer
pH range over which a particular acid and its conj. base can be effective
a buffer is most resistant to pH change when
[HA] = [A-]
buffer effectiveness decreases as
difference in HA and A- concentrations increase
higher (but equal) [HA] and [A-] causes
decreased pH change
effective range for a buffering system
pKa = ph ± 1
equivalence point
moles of base is stoichiometrically = to moles of acid
determine pH of a salt made of a weak acid + base
pH = 1/2 (pKw + pKa - pKb)
half equivelence point
pH = pKa
pKa > pKb
basic solution
pKa < pKb
acidic solution
pKa = pKb
neutral solution
calculate [H3O+] (strong base and acid titration)
(initial moles H3O+) - (moles OH- added) / total volume
calculate [O-] (strong base and acid titration)
(moles OH- added) - (initial moles H3O+) / total volume
before equivalence point (acid titration)
excess H3O+
after equivalence point (acid titration)
excess OH-
volume at equivalence point depends on (3)
initial amount of acid
base concentration
stoichiometry of the reaction
after titrating a weak acid with a strong base
solution becomes a buffer
half equivalence point (after adding strong base)
equal amounts of weak acid and conjugate base
at equivalence point
solution contains an ion acting as a weak base
weak acid + strong base titration
basic equivalence point
polyprotic acid titration
volume needed to reach equivalence point 1 = additional volume needed to reach equivalence point 2
larger Ka
smaller 1/2 equivalence point
larger Kb
higher pH at 1/2 equivalence point