CHEM1100 Experiment 5 Laboratory Report CLEAN CHEMISTRY- Determination of sodium percarbonate concentration by permananate ana!ysis Name *artner +roup
Emma "#itt!e Emi!y Lay *,
Student Number Demonstrator Date !ab comp!eted
$%&'$()$ C#ris Read %.,.$
Introduction/ Introduction/ State t#e purpose of t#e e0periment and bac1round2 Hydroen pero0ide 3H45467 3H45467 a 1ey inredient in !aundry deterents7 remo8es stains by actin as an o0idiser and brea1in up mo!ecu!es2 "#en sodium percarbonate is added to 9ater7 #ydroen pero0ide is re!eased2 In t#is e0periment7 9e 9i!! be in8estiatin t#e pairin of sodium percarbonate 9it# potassium permananate so!ution to effecti8e!y remo8e stains2 T#e purpose of t#e e0periment 9as to e0p!ore t#e reaction bet9een #ydroen pero0ide and permananate2 permananate2 T#e reaction unba!anced t#at yie!ds t#is reaction is: H;3a<6 ; H4543a<6 ; Mn5$- 3a<6 54 36; H453!6 ; Mn4;3a<6 =sin a =>- 8is spectroscopy7 9#ic# indicates t#e presence of a particu!ar species in a so!ution t#rou# absorbance7 absorbance7 t#e mo!ar ratio for t#e reaction and t#e concentration of H454 present in a samp!e of !aundry po9der 9i!! be determined2 Experimental Section/ Section/ Inc!ude a s#ort enera! description of t#e e0periment2 Remember to use t#e past tense2 Safety precautions ta1en: +!o8es7 c!osed in s#oes7 !ab coat7 safety !asses2 *art A and ? 9ere comp!eted and t#e resu!ts 9ere recorded7 needed for part C2 @irst!y to neutra!ise t#e base7 t#e so!utions 9ere prepared2 Around ,2%-,2$ of b!eac# po9der po9der 9as first measured measured and M su!furic su!furic acid so!ution so!ution 9as added unti! t#e fiin #ad come to a stop2 T#is so!ution 9as t#en added to a ,,mL 8o!umetric f!as1 and di!uted 9it# disti!!ed 9ater2 To create a second di!ution7 mL of t#e so!ution 9as added usin an automatic pipette into a 4&mL 8o!umetric f!as1 and fi!!in 9it# disti!!ed 9ater2 T#ree ,mL p!astic tubes 9ere prepared 9it# 42&mL of M H4S5$ 3a<6 and 42&mL of of $0, -$ M MBn5$ 3a<62 ?!eac# po9der so!ution of mL 9as added to eac# of t#e tubes 9it# an automatic pipette and fi!!ed to t#e ,mL mar1 9it# disti!!ed 9ater2 T#e absorbance 8a!ue on t#e ca!orimeter 9as reeroed to disti!!ed 9ater 9#ic# #ad been done in part ?2 T#e absorbance 8a!ues 9ere t#en measured for a!! t#ree tubes7 as done before on t#e ca!orimeter connected to Labuest2 T#e a8erae 9as ta1en from t#e t#ree absorbance 8a!ues and ca!cu!ations 9ere comp!eted to ca!cu!ate t#e stoic#iometry of t#e so!ution: 2 T#e number number of mo!es mo!es of Hydro Hydroen en *ero0id *ero0ide e in so!ution so!ution t#at t#at reacted2 reacted2 42 T#e Concen Concentrati tration on of Hydroen Hydroen *ero0 *ero0ide ide in t#e t#e t9o so!ution so!utions2 s2 %2 T#e number number of mo!es mo!es of Hydroen Hydroen *ero0ide *ero0ide in t#e acti8e acti8e o0yen o0yen !aundry !aundry po9der po9der22 $2 *ercenta *ercentae e by mass mass of Na4C5%2 Na4C5%22&H45 2&H454 4 in t#e !aundry !aundry po9der2 po9der2 A report report 9as 9ritten up2 up2
Results Section/ S#o9 t#e steps in your ca!cu!ations in eac# part2 =se t#e f !o9c#art on pae $ as a uide2 Remember to inc!ude appropriate 9or1in and units2
a2
A8erae absorbance from t#e trip!icate ana!ysis
0.069+ 0.072+ 0.063
A8erae
3
,2,' ?est fit E mL ,2,,L C2$0, -& . ,2,, ,2,$ mo!.L ∴
b2
Number of mo!es of H454 in so!ution 3use e
c2
FH454G in t#e di!uted b!eac# so!ution
d2
FH454G in t#e ,, mL b!eac# so!tion before di!ution
e2
Number of mo!es of H454 in t#e ,, mL b!eac# so!ution
f2
Number of mo!es of H454 in b!eac# po9der added
2
#2
i2
2
12
Mo!ar mass of H454
"ei#t of H454 in b!eac# po9der added
*ercentae of H454 in b!eac# po9der
Mo!ar mass of Na4C5%J2&H454
by mass of Na4C5%J2&H454 in b!eac# po9der
C>C4>4 3,2,$ 63,2,4&6 C43,2,,6 C4 ,2%& mo!.L
nC> n ,2%& 0 ,2 ,2,%& M
Same as t#e ,,mL b!eac# so!ution: ,2,%& M M" 340H6 ; 34056 3402,,'6 ; 340 &2)))6 %$2,$(.mo! M n 0 MM M ,2,%& 0 %$2,$( 24$
*ercentae 324$.,2%)6 0,, %''2(
M" 340Na6;3C6;350%6;2&3340H6;340566 M" 3442)')046;342,6;3&2)))0%6;3%$02&6 &(
n 3%2& 0 , -% M6.32&6 42$%0,-% m 42$%0,-% 0 &( ,2%' *ercentae 3,2%'.,2%)60,, )24
Discussion Section/ You must state t#e o8era!! 3main6 outcome of t#e e0periment2 Inc!ude an e8a!uation of any sources of error and ta1e into account #o9 t#ese mi#t #a8e affected your fina! resu!ts2 T#e outcome of t#e e0periment 9as to determine t#e concentration and stoic#iometry of sodium percarbonate by permananate ana!ysis2 It #as been ca!cu!ated t#at t#e #ydroen pero0ide present in t#e b!eac# po9er 9as %''2( and a!so t#e percent yie!d by mass of Na4C5%22&H454 in t#e un1no9n b!eac# po9der 9as )242 T#ese percentae mass cou!d not correct as it is o8er ,,7 t#is means t#ere is #i# inaccuracy in our resu!ts2 "#en t#is 9as compared to ot#er roups7 t#e inaccuracy 9as more e8ident since t#e resu!t s#ou!d be a muc# !o9er percentae around %,-$,2 T#is is t#e product of t#e reaction of #ydroen pero0ide and permaanate: H;3a<6 ; &H4543a<6 ; 4Mn5$-3a<6 K &5436 ; H453!6 ; 4Mn4;3a<6 T#ere 9ere many sources of error t#at cou!d #a8e affected t#e fina! resu!t2 An impactin inaccuracy 9as t#e preciseness of measurements to create eac# so!ution2 To impro8e t#is error7 an automatic pipette and 8o!umetric pump 9as used2 Ho9e8er7 errors 9ere introduced durin t#e di!ution and transfer of b!eac# po9der into t#e so!utions2 T#is error affected t#e accuracy of our stoic#iometry and as a resu!t our ca!cu!ations and percentae mass for t#e e0periment2 T#is 9ou!d furt#er affect t #e spectrometer and 9a8e!ent# if t#e measurements 9ere incorrect2 Anot#er reason t#e percentae 9as 8ery #i# cou!d be due to t#e !o9 absorbance a8erae from t#e trip!icate ana!ysis2 T#e =>-8is spectrometer may of needed a more often ca!ibration 9it# t#e disti!!ed 9ater to et a more accurate absorption 8a!ue2 Mu!tip!e tria!s may a!so impro8e accuracy and reduce t#e effects of random error2 Despite t#is error7 an accurate trend!ine and concentration radient 9as ab!e to be de8e!oped for absorption and t#e mo!ar ratio bet9een #ydroen pero0ide and permananate 9as ab!e to be ca!cu!ated2
References/ +o to t#e = Library 9ebsite2 In t#e Searc# bo07 type *ercarbonate as a #ydroen pero0ide carrier2 @o!!o9 t#e Har8ard referencin sty!e to pro8ide a fu!! reference for t#e artic!e for 9#ic# a8ier Ri8as is a co-aut#or2
Ca!!e7 R+7 +imeno7 57 Ri8as7 7 4,47 O*ercarbonate as a Hydroen *ero0ide Carrier in Soi! Remediation *rocessesP7 Environmental engineering science7 8o!2 4)7 pp2 )&-)&2
