PracticeExam3
1) Whatisabuffer?
2) Howdobufferswork?
3) Whatmakesagoodbufferintermsoftheselectionofsaltandacidandtheirratios?
4) WhatistheHenderson‐HasselbalchEquation?
5) WhatisthepHofabufferthatis0.200MHC
2
H
3
O
2
and0.300MNaC
2
H
3
O
2
iftheK
a
ofHC
2
H
3
O
2
is
1.8x10
‐5
.
6) WhatisthepHofabuffercomposedof0.200MHC
2
H
3
O
2
and0.250MNaC
2
H
3
O
2
in1.00Lthathas
0.020molNaOHaddedtoit?Assumethetotalvolumedoesn’tchange.
7) Whatarethebufferingcapacityandbufferingrangeofabuffer?
8) Whatwoulddestroyabufferintermsofitseffectiveness?
9) Whichoftheweakacidsfromyourtextwouldbethebestchoicetocombinewithitssodiumsaltto
makeabufferwithpH4.80?
10) WhatratioofNaCHO
2
:HCHO
2
wouldberequiredtomakeabufferwithpH4.00?Thepk
a
forFormic
Acidis3.74.
11) Istheequivalencepointlessthan7,7,orgreaterthan7for:
a. Titrationofastrongacidwithastrongbase?
b. Titrationofaweakacidwithastrongbase?
c. Titrationofaweakbasewithastrongacid?
12) WhatisthepHofasolutioncomposedof100mLof0.2MHClthathasbeentitratedwith25mLof
0.3MNaOH?
13) WhatisthepHof150mLof0.100MHCHO
2
beforeithasbeentitrated?Thepk
a
forFormicAcidis
3.74.
14) WhatisthepHof150mLof0.100MHCHO
2
thathasbeentitratedwith50mL0.200MNaOH?
15) WhatisthepHof150mLof0.100MHCHO
2
thathasbeentitratedwith75mL0.200MNaOH?
16) WhatisthepHof150mLof0.100MHCHO
2
thathasbeentitratedwith100mL0.200MNaOH?
17) Howdoindicatorswork?
18) WhatisexpressionforthesolubilityproductconstantforPbCl
2
?
19) CalculatethemolarsolubilityofCa(OH)
2
inpurewaterat25°C.K
sp
=4.68x10
‐6
.
20) DeterminetheK
sp
ofPbSO
4
ifitsmolarsolubilityinwaterat25°Cis1.35x10
‐4
M.
21) Howdoyouknowifaprecipitateformswhenyoupourtwosolutionstogether?
22) Whatarecomplexions?
23) Whichofthefollowingcompoundsfromthek
sp
tablefromyourtextwillhavethehighestandwhich
wouldhavethelowestmolarsolubilityinpurewater?
24) WhatistheFirstLawofThermodynamics?
25) Whatdeterminesthespontaneityofareactionorprocess?
26) Whatisareversibleprocess?
27) Whatisenthalpy?
28) Whatisentropy?
29) WhatdoesS=klnWmean?
30) WhatisW?
31) Whatisthedifferencebetweenamicrostateandamacrostate?
