Acid base equilibrium Flashcards
(24 cards)
Properties of acids
sour
turn litmus paper red
can conduct electricity
Properties of bases
bitter, feel slippery, turn litmus paper blue
Arrhenius theory
- all acids make H+ when in water, H+ makes acidic
2 all bases make OH in water, OH makes basic
3 explains neutralization reactions
limitations of Arrhenius theory
H+ does not exist in water, makes H3O ion
some bases do not have OH
not all salts are neutral
not all reaction occur in water
Bronsted-Lowry Theory
bases - accept H+
Acid - gives H+
acid base reaction is equilibrium
does not need to be in water
all Arrhenius acids are BL acids, same with bases
anything can be acid if another thing is base at same time
What are conjugate pairs
2 molecules that different in H+ ion only,
Conjugate base of acid is when H+ is removed from acid
conjugate acid of base is when H+ is added to base
amphiprotic vs amphoteric
amphoteric - neither acid or base (water )
amphiprotic - can donate or accept H+
all amphiprotic are amphoteric
not all amphoteric are amphiprotic
Ion product constant of water
kw = 1.0x10-14
lewis acid and base
uses electrons instead of H+
acids accept electron pair - eletrophile, does not need to have H
bases donate electron pair - nucleophile
what is lewis acid and base in reaction
acid - incomplete octet, simple cation, multiple bonds but 2 atoms of diff electronegs
acid is electron deficient
base is other one
strong acids/bases vs weak acids/bases
strong acid - completely dissociates in water, ions
weak - limited dissociated in water
conjugate of weak is strong, vise versa
what are 7 strong acids
HCl, H2SO4, HBr, HClO4, HClO3, HI, HNO3
sig figs of pH how
digit to left of decimal is not important
get sigfigs of concentration and used that for decimal places of pH
ex pH - 3.602059
2 sig figs
pH = 3.60
Explain the rule for increasing acid strength with oxyacid
if oxy and O atoms >2 stronger it is
by making it more polar
The greater the difference in
the number of H and O the stronger it is
Define the acid-ionization/acid-dissociation constant (Ka)
Ka, like Keq but ignore concentration of water
produce / reactant
strong acids have higher Ka
how much an acid dissociates in water
relationship between Pka and pH
pKa same relation ship with Ka and pH and H
can use ka to get pKA, lower the pKa, stronger the acids ability to donate protons
pKa is constant for each molecule, not affected by concentration
Distinguish between monoprotic and polyprotic acids
monoprotic - only 1 H dissociates in water
Polyprotic - More than 1 H dissociates, dissociates in steps,
Describe how hydrogens in polyprotic acids are ionized (Ka1, Ka2, and Ka3)
ka for each H ion that would leave in the neutralization reaction
each Ka is lower than the last
What is Kb, percent dissociation
base dissociate constant, amt dissociated
percent dissociation - [B]dissoc/ [B] init * 100%
how to get Kb from ka and kw
Kb = kw/ka
How is buffer solution made, what does it do
solution that resists change when acid or base added
weak acid and conjugate base or vice versa
made from acid and a salt to get the conjugate base
how do buffers work
HA <-> A- + H+
has equilibrium of weak acid and conjugate base
when a strong acid is added. H+ ions cause reaction to shift to favor the conjugate acid (Left). Will use up H+ ions with the base
if base added then OH reacts with weak acid, shifts reaction to right
Define burette, pipette, titrant, analyte, endpoint, equivalence
burette - holds titrant
pipette - used to add analyze into flask on bottom
titrant - known concentration, usually strong
analyze - unknown concentrations
equivalence - same amount of moles of H3O and OH reacted
endpoint - clear change in colour of indicator
