Aci dBaseExper i ment Det er mi nat i onofCaCO3 i nToot hpa st e MEMBERSGROU OUP Pa we e
No nt a mo mo ng k o l t o r n ( Ba nk )1 11
J at upat
Chant av i l as
( Fol k )111
War aphan Sume met awenunt
( Ev e) 111
Wa r a r a t
( Ey e )1 11
Su me me t a we nu nt
DATE:2 :27thFe br u ar y2 01 5
I NTROD ODUCTI ON
Acids cids and and base bases s are are su subs bsta tanc nces es that that can can be foun found d ever everyw ywhe herre in a simple everyday life. One of an example is the utensils which are usually in a form of a liquid substance. Most of them contain a concentration of acidic and basic however each kind and benets of them depends on its concentration anyways. CaCO3!"Cl—#CaCl!"!OCO! $or instance% the toothpaste. &t is actin' as a basic substance. Mostly produced from calcium carbonate% dehydrated silica 'els% hydrated alluvium oxides% ma'nesium carbonate% phosphate salts and silicates. &t’ s essential to your daily oral health care. (e use toothpaste to brush and clean our teeth. )ince% it is considered as the basic substance% so it has an ability to clean thin's like most of the other basic substance did. &t helps remove plaque and bacteria. *he +uoride contained in toothpaste also has the capability to prevent tooth decay it stren'thenin' the teeth. &n this experiment% we used toothpaste to test for a base in calcium carbonate. *here are are many theories that state about the di,erence di,erence of Acid and base. $irst is called -ewis *heory. &t denes that acidic substances have an ability to acce accept pt elec electr tron ons s whos whose e are are 'ive 'iven n by basi basic c su subs bsta tanc nces es.. )o% )o% the the basi basic c substances are the one who 'ives o, an electron to the acid one. elated to Arrhenius% Arrhenius% an acid is any substance that ionised in an aqueous solution that will produce the hydro'en ion. On the other hands% a base will produce "ydroxide ion. ion. An Anoth other er famous famous theor theory y is called called /ronst /ronsted0 ed0-o -owr wry y theory theory.. *his *his would would be di,erent from -ewis one because it focusses on the proton while -ewis focused on the electron of on a substance. *he /ronsted theory states that the proton will be 'iven o, by acids to the proton acceptor whose are the bases. ‘ *he molarity of acid can be dened by the method called *itration *itratio n’ . *his method is the process that determines the number of a substance by reactin' substance with a known amount of another substance. $or example% the usin'
the phenolphthalein color indicator. &t can dene the amount of Acid and /ase by a chan'e in colors of phenolphthalein indicator which tested on a substance. *his indicator allows us to see the chan'e in color% color% but not the number of p". &n this experiment% we use the procedure of back titration which we added the excess amount of the standard trident to the analyse. )o% it would be a bit di,erent between this two type of titration. PURPOSE 1 *o *o demonstrate the the titration technique 1 *o *o be able to calculate the molarity molarity by usin' the result result from titration 1 *o *o understand and be able able to read the titration titration’ s 'raph properly 1 *o *o nd the amount of of CaCO3 containin' in the toothpaste
HYPOT OTHESI S
Our "ypothesis are the color of the toothpaste solution will turn pinkish due to the reaction of the indicator and of "Cl in it. (e mi'ht see the chan'e in color when its p" reach around 2 to . And also% we should have 'ot the Calcium Carbonate in the toothpaste. MATERI ALS 1 3 of 4!5 m- 6rlenmeyer $lasks $lasks 7Conical $lask8 $lask8 •1s pa t u l a •1s t an dwi t hd oub l ebu r n th ol d er •1bur et •1s t i rbar •1pHmet er •1g r a du at e dc y l i n de r • Aheat er
METHODS
4. 9er 9ero sca scale le.. !. :ut 4!5m4!5m- 6rlenmey 6rlenmeyer er 7conical 7conical +ask8 +ask8 on scale. 3. (ei'h around ;.5; 'ram 'ram of toothpaste% toothpaste% usin' spatula% directly directly into 4!5m6rlenmeyer +ask. <. ecord ecord the wei'hed wei'hed value. value. 5. =sin' a 4;m4;m- 'raduated cylinder% cylinder% add 4; m- of "!; 7distilled water to to the toothpaste. >. =tilise a 4;.;; mm- volumetric pipette% pipette% pipette exactly exactly 4;.;; m- of ;.4; M "C- 7"ydrochloride acid8 into toothpaste?water solution. 2. Add a stir stir bar% heat and stir stir for 5 minutes minutes on hotplate. hotplate. @. emove emove from heat heat and let let it cool down. down. . Add few drops drops of :henolphthalein indicator. indicator. 4;.)tarin' addin' your titrant 7;.4;M aO" 7)odium "ydroxide8 "ydroxide8 in buret8 slowly. 44.Check the p" after every 4m- of titrant added. 4!.ecord 4!.ecord both the initial volume and initial p". 43.(hen solution starts to turn pink but return to transparent% clear after swirlin'% add slower 7drop0wise perhaps8.Af perhaps8.After ter end point has been reached% record record the nal p" and nal volume. 4<.Continue addin' titrant% an additional < m- of titrant. 45.A'ain checkin' the p" after every 4 m- has been added. 4>.epeat experiment experiment ! more times. *his will 'ive a total of 3 separate titrations. 42.Bispose of your waster in lar'e beaker provided% do not dispose of down the drain.
[email protected] left over aO" solution in buret after use. DATA/ RESUL TS:T ABLE1( COL OLLECTI NG FROM OM THEEXPERI MENT)
We i ghtt oot hpa st e( g) I ni t i a lVol ume( mL) I ni t i alpH Fi nalVol ume me( mL) Fi nalpH ( mL) Tot alVol ume me( mL) Vol ume meHCLr eact ed wi t ht oot hpa st e Mol esHCLr eact ed
Sampl e1( 20mLHCL)
Sampl e2( 30mLHCL)
Sampl e( 30mLHCL)
0. 48g
0. 43g
0. 47g
32. 52mL
39. 50mL
44. 81mL,40. 18mL
1. 98
2. 51
2. 46
39. 50mL
44. 81mL
49. 73mL,41. 49mL
9. 97
8. 02
7. 94
6. 98mL
5. 31mL
6. 21mL
3.02
4.69
5.08
3.02 x 10 -4
4.69 x 10 -4
5.08 x 10 -4
Mol esCaCO3 Amo mountCaCO3 ( mg) Amo mountCaCO3( mg/ g)
Sampl e1( 20mLHCL)
Sampl e2( 30mLHCL)
Sampl e( 30mLHCL)
1.51 x 10 -4
2.35 x 10 -4
2.54 x 10 -4
15.1
23.5
25.4
31.46
54.65
54.04
Ave r ageCaCO3 ( mg/ g)
46.71
St a nda r dDe v i a t i on
13.28
%RSD
28.66
p" and the amount of aO"
DI SCUSSI ON
This experiment is about using the Titration method to find out for the a! 3 "ontaining in the toothpaste. #t is some $ind of "hemi"a% ana%&sis pro"ess so the heating method ta$es a 'er&
important ro%e in this method. The first step that (e did in the beginning of the experiment is (e (eigh the toothpaste and then pour the disti%%ed (ater into it. )fter that (e heated the so%ution. The purpose* of heating the so%ution (as to e'aporate or to remo'e the arbon dioxide out from the so%ution. +oreo'er* the heating pro"ess a%so he%ps in in"reasing the rate of rea"tion (ithin the so%ution. The in"rease in temperature (ou%d ma$e the a! 3 and ,% rea"ted bet(een ea"h other easier and ui"$er. #t he%ps e'aporation of ! 2 happen ui"$%& be"ause ! 2 "an ma$e "hange "hange in in the resu%t. The se"ond step (as added to the a"id and base to the so%ution in order to go on the pro"ess of titration. e added an a"id so%ution (hi"h is ,% to find the amount of a%"ium arbonate "ontained in the so%ution. The method (as that (e mixed the ,% (ith the toothpaste* the ,% (i%% rea"t (ith the toothpaste* some of them did and some of them did not. Then fo%%o( b& /a!,* (e added /a!, (hi"h is a basi" so%ution to titrate (ith the remaining ,% (ithin the toothpaste so%ution* (hi%e ea"h of the a"id and basi" so%ution (e added into the toothpaste "ontained the same amount. )fter the& rea"ted to ea"h other* (e (i%% be ab%e to determine an amount of a! 3 (ithin the toothpaste b& dedu"ted to the amount of /a!, (hi"h (e added the eua% amount as the ,%. )t the time (e putted /a!, into the so%ution. e "an see that the "o%or of it (i%% s%ight%& "hange of pin$ish "o%or. This is "a%%ed an end point (hi"h is 'er& important part of the Titration method. #t is the point (hen the "o%or of the so%ution in a f%as$ turned to some $ind of pin$ish "o%or that "an be noti"ed. )nd as the f%as$ (as stirred* it (ou%d be a %itt%e tough to see it immediate%& be"ause the "o%or "hange so ui"$%&. ,o(e'er* another point (hi"h a%so re%ated re%a ted to the end point of this pro"ess (hi"h is as important as the end point is "a%%ed an eui'a%en"e point. This (as (hen both so%utions (ere added in the same amount amount that (i%% be sho(n after the "hanging in "o%or. "o%or. )s (e "an be "%ear from the experiment that the time (hen the so%ution turned pin$ is "a%%ed an end point. or our group* the so%utions "o%or turned to pin$ at the p, of 7.94. )s (e added the indi"ator to the so%ution* in this "ase (e use heno%phtha%ein. e dropped into the so%ution that (i%% determine the so%ution (hether it is an a"id or base after afte r the "o%or (as "hanged. )nd the reason (h& it turned pin$ be"ause of its "hara"teristi" that (i%% rea"t (ith the so%ution. The heno%phtha%ein (i%% sho( pin$ish "o%or (hen the so%ution s%ight%& basi". )""ording to our experiment* the so%utions "o%or turn pin$ (hen the 'o%ume of /a!, (as 51.24 m. in"e (e did the experiment three times be"ause (e tried to be a""urate (ith the resu%t. #t (i%% be more a""urate (ith three samp%es rather than on%& one samp%e (as tested. o* thats (h& three rep%i"ates performed* in order to obtain the most a""urate amount of a! 3 (e need to a'erage three numbers together. )%so* as this (as our first time doing this experiment* some of the step "ou%d be a mess up or in"orre"t. o (e (i%% ha'e another "han"e to do it again for a "orre"t step and the (a& of using the euipment. To ensure the amount of a! 3 b& the a'erage of the three times experiment. CONCLUSI ON
)fter (e ha'e done the experiment* (e %earned about the Titration method (hi"h (e used to find the amount of a%"ium arbonate "ontained in the toothpaste (e brought to test. epending on our h&pothesis that (e state at first that there (ere a%"ium arbonate in the toothpaste and a%so the "o%or of the so%ution (i%% turn to a $ind of pin$ "o%or (hen the amount of p, rea"hed around 7 to 9. )nd (e found that the resu%t of our experiment fo%%o(s the h&pothesis. ,o(e'er* this (as the first
time of our group to do the experiment* some of the step (oman not do it "orre"t%& or the euipment (e (ere not used it "orre"t%& %eads to some errors to our experiment. There (ere some errors during the experiment (hi"h made the resu%t s%ight%& "hange from (hat it shou%d be or from (,at (e expe"ted. The first error (as the fa"t that (e "annot a"tua%%& stop or pause the amount of /a!, dropped into the so%ution immediate%& at the time that the "o%our (as "hanged. )nd sometimes (e a%so did not rea%%& noti"e the "hange in "o%our of it be"ause the "o%our "o%our "hanged so ui"$%& and at the same time the "o%our got too dar$ so fast too. & obser'ed it (ith a na$ed e&es* it ma& not be so a""urate but (e tried our best to ma$e it the most stab%e 'a%ue. #t is a%so the first time that (e ha'e tried this $ind of experiment* some of the euipment and so%utions is uite mess up at the beginning. )nother error that (e'e found (as on the p, meter. e thought its not fun"tioning proper%& be"ause as (e added more of /a!, to the toothpaste someho( the p, sti%% remained the same. e de"ided to "%ean it again and again unti% the p, "hanged as the on%& (a& (e "an do to so%'e this prob%em. There (as one more prob%em in the experiment. e didnt get to the p, of 12 be"ause (e thought that the p, meter (asnt (or$ing 'er& (e%%. #t might be the un"%ean of it that %o(er its abi%it& to determine p,. Thats (h& the graphs shape is not %i$e%& to be but ust a "ur'e that if (e "ontinuous%& on to it* (e "an see the shape of the graph (hi"h is %i$e%& to be . REFERENCES
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huP)Hx<" L*GuCM>huP)Hx<"wCAKvedJ;C/ wCAKvedJ;C/wP>A6wAAQvJonepa' wP>A6wAAQvJonepa'eK eK DMonday% 0 March0!;45 March0!;45 42.<; 6)*E yane% /. 7!;45% $eburary !28. Acid /ase -ab Betermination of CaCO3. Mahidol =niversity &nternational Bemonstrated )chool.
*itration DOnlineE. DOnlineE. Available Available ht t p: / / c hemwi k i . uc dav i s . edu/ Anal y t i c al _Chemi s t r y / Quant i t at i v e_Anal y si s / Ti t r at i on D$riday% >0
March0!;45 March0!;45 4<.42 6)*E )pecialty Minerals Calcium Carbonates in *oothpaste and Oral Care :roducts DOnlineE. Available http??www.mineralstech.com?:a'es?)M&?*oothpaste.aspx D$riday% >0Mar0!;45 4<.;3 6)*E =nknown 7o Bate8. Bate8. 6xperiment 6xperiment 2 titration of of an antacid DOnlineE. Available Available http??www.bc.edu?schools?cas? http??www.bc.edu?schools?cas?chemistry?under chemistry?under'rad?'en?fall?* 'rad?'en?fall?*itration.pdf itration.pdf DMonday% 0March0!;45 4@.!< 6)*E.
