CHM 142 Exam 2 Flashcards
Are pure solids and pure liquids written into Keq equations?
No, they have a value of 1 because their activity is 1
they have constant concentration
Reactant Quotient
similar to Keq but concentrations used can be from any point in the reaction
Q»K
reaction proceeds left, forming more reactants
right to left
Q«K
reaction proceeds right, forming more products
left to right
Q= K
reaction must be at equilibrium
Which way does the reaction proceed if the volume is decreased and pressure is increased?
the reaction will shift in the direction of less moles
which way does the reaction proceed if the pressure is decreased and the volume is increased?
The reaction will shift to the side that produces more moles
For an exothermic reaction (H is -) that has heat taken from the system, which way does it proceed?
exothermic = reactants— products + heat so the reaction moves right
increases K
For an endothermic reaction (H +) that has heat added to the system, which way does it proceed?
endothermic = reactants + heat—products so the reaction shifts to the right
Increases K
How does a catalyst affect equilibrium?
it does not affect Keq but it does get the reaction to meet eq faster than without it
Arrhenius Acid
Increases the concentration of H+ ions
Arrhenius Base
Increases the concentration of OH- ions
Bronsted-Lowry acid
proton donor
Bronsted Lowry base
proton acceptor
a substance that can be both an acid and a base with the right electron configuration and # of H+ ions
Amphiprotic
Conjugate base
-1 H+ from an acid
Conjugate acid
+1 H from a base
the stronger the acid the —- its conjugate base
weaker
the stronger the base the—its conjugate acid
weaker
In acid-base rxns what will eq favor?
the transfer of the proton from the stronger acid to the stronger base to form a weaker acid and weaker base
when water donates protons to other water molecules
Autoionization
Kw, Ion product constant
the eq constant for ionization of water
1.*10^-14
what kind of solution is it when [H+]>[OH-]
acidic
what kind of solution is it when [H+]<[OH-]
basic
pH=
-log[H+]
pOH=
-log[OH-]
14.00=
pH+pOH
true or false? everytime you move up a unit on the pH scale the [H+] increases *10
false, everytime you move down a unit on the pH the concentration increases *10
a strong electrolyte that completely dissociates into H+ ions
strong acid
a strong electrolyte that completely dissociates into OH- ions
strong base
for strong monoprotic acids [H+]=
[base]
for diprotic strong bases [OH]
= 2*[base]
weak electrolytes that only partially dissociate into H+
weak acids
what do weak acids do that strong acids dont?
they establish equilibrium
the — the values of Ka the — the acid
larger, stronger
[H+]=
strong acid
[acid]
[H+]<
weak acid
[acid] initial
percent ionization for HA
[H+]eq/[HA]eq *100
ionization equation for weak acids
HA (aq)—[H3O+]+[A-]
weak bases
partially dissociate into OH- ions + a conjugate acid in water
Kb=
[CA+][OH-]/[B]
What are the two types of weak bases?
- neutral substances that have a nb pair of electrons to accept the proton (typically have a N atom)
- anions that are conjugate bases of a weak acid
[Ka]*[Kb]=
1.0*10^-14
pKa+pKb=
14.00
Cations can be — and —-
acidic and neutral
Anions can be —,— and —
acidic, basic, and neutral
are anions from a strong acid neutral, basic or acidic
neutral
are anions from a weak acids basic, acidic or neutral
basic
are anions from a polyprotic acid bases, acids or neutral
they can be both
compare Ka and Kb
are cations from strong bases acidic or neutral
grp I and grp II cations
neutral
are conjugate acids from weak bases acidic or neutral
acidic
are transition and post transition metal cations acidic or neutral
acidic
neutral ion + basic ion=
basic solution
basic ion+ acidic ion=
compare Ka and Kb values
the larger values determines pH level
