CHEMISTRY LABORATORY REPORT Experiment 4: CHEMICAL EQUILIBRIUM
To: Instructor: PhD Hoang Le Son From: Do Truong Anh Thu - Student ID: BTBCIU14046 Subject: General Chemisr! La"oraor! Date: #$o"er 1% h& %01'
I. INTRODUCTION
This e()erimen ells us he *a! o i+eni,! an+ o"sere he $hange o, he reersi"le rea$ion a e.uili"rium *hen a))l!ing sresses an+ e()lain hose $hanges "! he Le Chaelier/s Prin$i)le hen he rae o, he ,or*ar+ "a$2*ar+ rea$ion "e$omes e.ual o he rae o, "a$2*ar+ rea$ion& he reersi"le is a e.uili"rium I, a s!sem a e.uili"rium is su"3e$e+ o a $hange o, )ressure& em)eraure o, he $on$enraion o, he $om)onens& here *ill "e a en+en$! ,or he ne rea$ion in he +ire$ion ha agains he e,,e$ o, his $hange Le Chaelier/s Prin$i)le5 II. PROCEDURE A. Instruments:
#ne '0 mL "ure
T*o es u"e hol+ers
#ne 10 mL )i)e
#ne es u"e ra$2
#ne '0 mL gra+uae+ $!lin+er
#ne me+i$ine +ro))er
T*o T*o %'0 mL "ea2ers
I$e "ah
T*o T*o 1'0 mL "ea2ers
aer "ah
#ne sirring ro+
La"el
T*en! es u"es
B. Exer!menta" Procedure:
1 S#stem $: A$i+ "ase e.uili"rium A++ 10 +ro)s o, $on$enrae+ HCl in o a $lean es u"e *hi$h has 10 +ro)s o, 0' 7 8 %Cr#4 9e$or+ !our o"seraion A,er ha& a++ more ' +ro)s o, 6 a#H #"sere he $hange o, $olor
% S#stem %: ;.uili"rium o, a$i+ "ase in+i$aors A++ %0ml o, +isille+ *aer ino a $lean es u"e *hi$h has % +ro)s o, meh!l iole& mi( hem *ell The soluion *as +ii+e+ ino % es u"es
-
Tes Tes u"e 1 *as a++e+ nohing
-
Tes u"e %: < A++ he 6 7 HCl soluion +ro) *ise unil ,urher a++iion resuls in no signi,i$an $hange #"sere he $hange < A++ he 6 7 a#H soluion +ro) *ise unill ,urher a++iion resuls in no $olor $hange #"sere he $hange < Again a++ he 6 7 HCl soluion +ro) *ise unil ,urher a++iion resuls in no sini,i$an $hange #"sere he $hange = S#stem &: Com)le( ion ,ormaion Pre)araion o, iron III5 hio$!anae soluion: in a 1'0 mL "ea2er& )la$e 10 mL o, 01 7 >eCl= an+ 10 mL o, 01 7 8SC& an+ hen a++ '0 mL o, +isille+ +isille+ *aer& mi( *ell Dii+e he soluion eenl! among 6 similarl!-si?e+ es u"e @1-5
-
Tes Tes u"e @1: $onrol5 a++ nohing
-
Tes u"e @%: a++ % mL o, 01 7 >eCl= o he soluion #"sere he $hange
-
Tes u"e @=: a++ % mL o, 01 7 8SC o he soluion #"sere he $hange
-
Tes Tes u"e @4: a++ 10 +ro)s o, 6 7 A#H o he soluion Des$ri"e he $hange in he soluion
-
Tes u"e @': $ool he es u"e in an i$e "ah
-
Tes Tes u"e @6: *arm he es u"e in a ho *aer "ah Com)are he inensi! o, he $olor in es u"e @1 $onrol- room em)eraure5& @' $ol+5 an+ @6 ho5
-
Tes Tes u"e @: a++ a ++ 01 7 Ag#= soluion +ro) "! +ro) unill u nill all he $olor +isa))ears 9e$or+ o"seraions 4 S#stem ': ;.uili"rium o, )re$i)iaion rea$ions ' mL o, 00' 7 CaCl% *ere )u ino ea$h o, he *o es u"es la"ele+ @1 an+ @%
-
Tes u"e @1: a++ 1 mL o, 01 7 a%C%#4 soluion #"sere he $hange
-
Tes u"e @%:
< A++ 1 mL o, 01 7 H%C%#4 #"sere he $hange& $om)aring o he es u"e @1 < A++ 10 +ro)s o, 6 7 HCl #"sere he $hange < A++ 10 +ro)s o, 6 7 H4#H #"sere he $hange ' S#stem (: Tem)eraure Tem)eraure e,,e$s on e.uili"ria = mL o, 01 7 CoCl% *as )u ino a 1'0 mL "ea2er A++ $on$enrae+ HCl +ro) *ise unil he soluion urns a )ur)le-iole $olor I, he s!sem urns a +ee) "lue& in+i$aing oo mu$h $hlori+e& +is$ar+ he soluion an+ sar again Dii+e he soluion e.uall! ino hree es u"es la"ele+ @1-=
-
Tes Tes u"e @1: $onrol5 2ee) a room em)eraure
-
Tes u"e @%: )la$e in a ho *aer "ah #"sere he $hange
-
Tes Tes u"e @=: )la$e in an i$e-*aer "ah #"sere he $hange
S*i$h es u"e % = #"sere he $hange Allo* hem "oh o $ool o room em)eraure Com)are o he $onrol
III. DATA AND DISCUSSION $. ACID)BASE E*UI+IBRIA
;.uili"rium S!sem: %CrO'% , %-,a/0
Descr!t!on o2 cond!t!ons
Pred!cted outcome
Cr%O1% , -%O"0
Obser3at!on
Ex"anat!on
Iniial soluion The $olor +oes The $olor is sill !ello* no $hange
The rea$ion is in e.uili"rium
< Con$ HCl
The $o $olor $hanges o orange
The $olor $hanges ,rom !ello* o orange
The $on$enraion o, he rea$an H<5 in$reases& so he rae o, ,or*ar+ rea$ion in$reases The rea$ion shi,s o he he righ righ&& an+ an+ )ro+u )ro+u$e $ess more more %Cr %# orange5
< 6 a#H
The $olor $hanges "a$2 o he iniial $olor
The $olor $hanges ,rom orange o !ello*
The $on$enraion o, he )ro+u$ #H-5 in$reases& so he rae o, "a$ "a$2*ar+ rea$ion in$reases The rea$ion shi,s o he le, e, an+ an+ )ro+ )ro+u$ u$es es more ore Cr#4%- !ello*5
%. E*UI+IBRIA OF ACID)BASE INDICATORS INDICATORS
;.uili"rium S!sem: -450a/0 , -%O"0
-&O,a/0 , 45 a/0
Add!t!on
Pred!cted outcome
Obser3at!on
Ex"anat!on
one $onrol5
The $olor +oes no $hange
The $olor is sill iole
6 7 H Cl
The $olor $hanges
The $olor $hanges ,rom iole o "lue& ,rom "lue o green
The $on$enraion o, H< in$reases an+ he rea$ion shi,s o he le,
6 7 a#H
The $olor $hanges o iole
The $olor $hanges ,rom green o iole
The #H- o, a#H rea$s *ih H< so he $on$enraion o, H< in he soluion +e$rease so he rea$ion shi,s o he righ
6 7 H Cl
The $olor $hanges
The $olor $hanges ,rom iole o green
The $on$enraion o, H< in$reases again *hen a++ing HCl ino he soluion& an+ he rea$ion shi,s o he le,
&. CO4P+E6 ION FOR4ATION
;.uili"rium S!sem: Fe&, , SCN
Pale !ello*5 Add!t!on
Pred!cted outcome
7FeNCS8 %,
Clear5
9e+5
Obser3at!on
Ex"anat!on
one $onrol5
The $olor +oes no $hange
The $olor is sill orange
The rea$ion is a e.uili"rium
0017 >eCl=
The $olor $hanges o re+
The $olor $hanges ,rom orange o ligh re+
hen in$reasing >e=< "! a++ing >eCl=& he s!sem shi,s o he righ an+ >eCS%< in$reases
001 001 7 8SC 8SC
The The $ol $olor or $hanges o re+
The $olor $hanges ,rom orange o +ar2er orange
hen in$reasing SC- "! a++ing >eCl=& he s!sem shi,s o he righ an+ >eCS%< in$reases
67 a#H
The $olor $hanges o
The $olor $hanges ,rom orange
hen a++ing a#H ino he soluion& #H- rea$s *ih >e=<
!ello*
o )ale !ello*
o ,orm he )re$i)iae& so he $on$enraion o, >e=< +e$reases an+ he s!sem shi,s o he le,
Col+
The $olor $hanges o re+
The $olor $hanges ,rom orange o +ar2er orange
This s!sem is e(ohermal rea$ion& *hen he em)eraure +e$reases& he s!sem shi,s o he righ an+ in$reasing >eCS%<
Ho
The $olor $hanges o !ello*
The $olor $hanges ,rom orange o )ale !ello*
hen he em)eraure in$reases& he s!sem shi,s o he le, an+ in$reasing >e=< SC-
017 Ag#=
The *hie )re$i)iae a))ears
>ormaion o, *hie )re$i)iae an+ *hie soluion
#$$urring he rea$ion: Ag< < SC- E AgSCF *hie5 The s!sem shi,s o he le, +ue o he +e$rease o, SC-
'. E*UI+IBRIA E*UI+I BRIA OF PRECIPITA PRECIPI TATION TION REACTIONS REACTI ONS
;.uili"rium S!sem: Ca%,a/0 , C%O'% a/0
Add!t!on
Pred!cted outcome
Obser3at!on
CaC%O's0
Ex"anat!on
a%C%#4 E %a< < C%#4%01 7 a%C%#4
hie )re$i)iae
>ormaion o, *hie )re$i)iae an+ li.ui+ "e$omes $olorless
C%#4%- < Ca%< E CaC%#4 The s!sem shi,s o he righ
01 7 H%C%#4
>ormaion o, *hie )re$i)iae an+ li.ui+ has ligh *hie $olor
Pre$i)iae is +issole+
The $olor $hanges ,rom ligh *hie o $olorless
H< ,rom HCl rea$s *ih C%#4%o ,orm H%C%#4& so he C%#4%- +e$reases an+ he s!sem shi,s o he le,
hie )re$i)iae
>ormaion o, *hie )re$i)iae an+ *hie li.ui+
#H- ,orm H4#H rea$s *ih Ca%< o ,orm *hie )re$i)iae Ca#H5%& so he Ca%< +e$reases an+ he rea$ions shi,s o he le,
6 7 HCl
6 7 H4#H
H%C%#4 E %H- < C%#4%-
hie )re$i)iae
The $on$enraion o, C%#4%in$rease an+ he rea$ion shi,s o he righ
(. TE4PERATURE EFFECTS ON E*UI+IBRIA
;.uili"rium S!sem: Co-%O09 !n0
Descr!t!on o2 cond!t!ons Not;!n< c;an
-ot =ater bat;
%,
a/0 , 'C" a/0
CoC"'
%
a/0 , 9-%O"0
dee b"ue0
Pred!cted outcome
Obser3at!on
Ex"anat!on
The $olor is )in2
The $olor $hanges o iole
The Cl- a++ing ,rom HCl is no enough ,or he s!sem so he soluion urns o iole
The $olor is "lue
The $olor $hanges o "lue
This s!sem is en+ohermal rea$ions& *hen in$reasing em)eraure he rea$ion shi,s o he righ an+ he [CoCl4]%− in$reases
Ice>=ater
The $olor is
The $olor $hanges ges o )in2
hen +e$ +e$reasing em)er )eraure
bat;
)in2
he rea$ion shi,s o he le, an+ he [CoH%#56]%< in$reases
I5. CONC+USION:
During ' e.uili"rium s!sems a"oe in his e()erimen& *hen *e a))l!ing sresses in ea$h o, rea$ion& he rea$ion *ill shi, o he +ire$ion ha re+u$e he e,,e$ o, his $hange a$$or+ing o he Le Chaelier/s )rin$i)le I, *e 2no* he righ +ire$ion o, rea$ion& *e $an $onrol& raise o, re+u$e he )ro+u$s as he *a! *e *an
