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A. TITLE OF EXPERIMENT
*Titrimetry*
B. OBJECTIVE OF EXPERIMENT
1. Students can understand the standardization of HCl solution.
2. Students can understand the determination of carbonate and bicarbonate
mixture.
C. LITERATURE REVIEW
The term ‘titrimetric analysis ‘ refers to quantitative chemical analysis
carried out by determining the volume of a solution of accurately known
concentration which is required to react quantitatively with a measured
volume of a solution of the substance to be determinate. The solution of
accurately known strength is called the standard solution. The weight of the
substance to know be determined is calculated from the volume of the
standard solution used and the chemical equation and relative molecular
masses of the reading compounds (vogel, 1989: 257).
In order to obtain accurate quantitative data for a reaction in solution, it is
necessary that the reaction be fast, complete and occur in fixed, reproducible
amounts. The requirement for fast reaction is achieved readily when ionic
species are involving, although in some other cases, it is necessary to warm
the solution or add a catalyst. The reaction will be complete provided the
equilibrium constant is large. The technique of volumetric analysis is the

simple type of titrimetry, and involves the addition of controlled volumes of a
reagent solution the titrant, to a known volume of another solution, the titrand
in a volumetric titration. This procedure may be automated, and the changes
detected instrumentally. In some cases, excess of a reagent is added and the
axcess measured by back titration ( kealey, 2005 : 80)
The term ‘volumetric analysis’ was formerly used for this form of
quantitative determination but it has now been replaced by titrimatric analysis.
It is considered that the latter express the process of titration rather better, and
the former is likely to be confused with measurement of volumes such as

these involving gases. In titrametric analysis the reagent of known
concentration is called the titrant and the substance being titrated is called the
titrand. The alternative name has nt been extended to apparatus used in the
various operations; so the term volumetric glassware and volumetric flasks are
still common, but it is better to employ the expressions graduated glassware
and graduated flasks and these are used throughout this book (vogel, 1989 :
257)
For a titration to be accurate we must add a stoichiometrically
equivalent amount of titrant to a solution containing the analyte. We call this
stoichiometric

mixture

the

equivalence

point.

Unlike

precipitation

gravimetry , where the precipitant is added in excess, determining the exact
volume of titrant needed to reach the equivalence point is essential. The
product of the equivalence point volume, veq and the titrant’s concentration,
Ct, gives the moles of titrant reacting with analyte.
Moles titrant=
Knowing the stoichiometry of the titration reaction (s), we can calculate the
moles of analyte (Harvey, 2000 : 274).

Provided that the end point coincides with equivalence point or the
stoichiometry of the reaction studied, theamounts of titrant and titrand
measured should correspond to the actual amount present.
For a general reaction:
aA + bB  cC + dD
A moles of a react with b moles of B to produce c moles of C and d moles of
D. A molar solution contains 1 mole of solute per 1000 cm (or 1 L) of
solution. Therefore, 1 cm of a 1 M solution contains 1 mmol of solute
( kealey, 2000: 81)
In volumetric analysis, in which the substance react on equivalence
bases. The point of equivalence (end point) is detected by suitable indicator.

The best indicator is one which gives the clear and sharp end point (easily
discernable) at the exact equivalence point of reacting substance (angelova,
2007: 437).
The reactions employed in titrimatric analysis fall into four main
classes. The first three of these involve no change in oxidation state as they
are dependent upon the combination of ions. But the fourth class, oxidationreduction reactions, involves a change of oxidation state or, expressed another
way, a transfer of electrons.
1. Neutralization reactions, or acidimetry and alkalimetry. These include the

of titration of free bases, or those formed from salts of weak acids by
hydrolysis, with a standard acid (acidimetry), and the titration of free
acids, or those formed by the hydrolysis of salts of weak bases, with a
standard base (alkalimetry).
2. Complex formation reaction. These depend upon the combination of ions,
other than hydrogen or hydroxide ions, to form a soluble, slightly
dissociated ion or compound, as in the titration of a solution of a cyanide
with silver nitrate () or of chloride ion with mercury (II) nitrate solution ().
3. Precipitation reactions. These depend upon the combination of ions to
form a simple precipitate as in the titration of silver ion with a solution of
a chloride
4. Oxidation-reduction reactions. Under this heading are included all
reactions involving change of oxidation number or transfer of electrons
among the reacting substance (vogel. 1989: 259).
Mixture determination of carbonate and bicarbonate beside used titration it
can also used two indicators namely PP and MD, can determined accurately
from sampling both of them. The first is titrated with solution of HCl standard
into MD indicator directly. To determine total of bases in sample. The second,
add BaCl2 to make carbonate precipitated , then doing titration with solution

of HCl standard 0,1 N by added MD indicator, to determined bicarbonate in
sample (Tim dosen, 2014:12).
The effective titrant concentration normally differs from the nominal
concentration due to either inaccurate preparation, purity of titrant used, or
changed due to instability. The effective concentration is determined by means
of a titer determination or a titration of a substance of exactly known
concentration usually a primary standard. It is essential to perform a titer
determination on all titrants before used for the first time. This also applies to
purchase reagents of certified concentration since the titer determination not
only compensates for concentration errors but also any minor burette
inaccuracies. This is a particular importance with corrosive bases since they
attack the glasses walls 01 the burette resulting in small volume changes
(John, 2001: 33).
Titration was carried out until color changes from colorless to pale
pink. Results were obtained in triplicate for standardization using the
following formula --------, (where N1 and V1 are the normality and N2 and
V2 are unknown normality ( Asrelly, 2012: 765).
Although

molar

concentration

are

now

commonly

used

in

determinations of reacting quantities in titrimetric analysis, it has been
traditional to employ other concepts involving what are known as “equivalent
weights” and “normalities” for this purpose. In neutralization reactions the
equivalent weight/normality concept is relatively straight forward, but for
reduction- oxidation titrations it often requires an understanding of what are
known as “oxidation numbers” of the substance involved in the redox reaction
( Vogel, 1989: 260).

For reactions such as a strong acid neutralizing a strong base, the
change at the end point is large, and the rate of change with volume is very
great, as shown by derivative plot. (Kealey, 2005: 82).

D. APPARATUS AND CHEMICALS
1. Apparatus
a. Beaker 500 ml

1 unit

b. Volumetric flask 250 ml

1 unit

c. Analytical balance

1 unit

d. Erlenmeyer flask 250 ml

6 units

e. Pipette

3 units

f. Volumetric pipette

2 units

g. Funnel

2 units

h. Washing bottle

1 unit

i. Spatula

1 unit

j. Watch glass
k. Stative and clamp

1 unit
@

2 units

l. Burette

2 units

m. Aluminium foil

1 piece

n. Filtering paper

3 pieces

o. Tissue
2. Chemicals
a. Solution of concentrated chloride acid 0,1 N ( HCl)
b. Indicator of methyl orange (MO)
c. Aquadest (H2O)
d. Borax (Na2B4O7.10H2O)
e. Solution of chloride barium (II) 10 % (BaCl2)
f. solution of mixture sample
E. WORK PROCEDURE
1. Standardization of HCl Solution.
a. 0,4035 g of Na2B4O7.10H2O was weighed in analytical balance and it
was diluted in volumetric flask until 100 ml of H2O (aquadest)

b. 25 ml of solution was taken by volumetric pipette into Erlenmeyer
flask (used 3 Erlenmeyer flask).
c. 3 drops of MO indicator was added by pipette into each Erlenmeyer
flask
d. Titration was done with standard solution until the color changed and

titrant volume was written
e. The average of titrant volume was calculated and concentration of
standard chloride acid (HCl) was determined
2. Determination of Carbonate and Bicarbonate Mixture.
a. 25 ml solution of mixture sample was placed in Erlenmeyer flask by
funnel ( used 3 Erlenmeyer flask)
b. 3 drops of MO indicator was added by pipette into each Erlenmeyer
flask
c. Titration was done with standard solution of chloride acid (HCl) 0,1 N
until the color changed snd titrant volume was written (for 3
Erlenmeyer flasks)
d. The average of titrant volume was calculated as V1
e. 25 ml solution mixture sample was placed in Erlenmeyer flask by
funnel (used 3 Erlenmeyer flasks) and drops of chloride barium (II) 10
% (BaCl2) was added by pipette into each Erlenmeyer falsk
f. The precipitate was let down and it was filtered by funnel and filtering
paper \
g. The filtrate was collected in other Erlenmeyer flask
h. Indicator of MO was added by pipette into each Erlenmeyer flask
i. Titration was done with standard solution until the changed of color
and titrant volume was written
j. The average of titrant volume (from 3 Erlenmeyer flasks) was
calculated as V2

k. Amount of carbonate (CO3-) and amount of bicarbonate (HCO3-) were
determined
F. OBSERVATION RESULT
No
1

Activity
Standardization
of
solution

:

0,4035

Result
HCl
g

Na2B4O7.10H2O was weighed 
diluted by water in volumetric
flask until 100 ml  took this
solution by used volumetric
pipette 25 ml into Erlenmeyer


prepared

3

Erlenmeyer

flasks (each flask contained 25
ml )  added 3 drops of MO

-

MO)  yellow solution

(each Erlenmeyer flask)  did

(added

titration with HCl as standard
solution.
a. Titration I

Colorless solution  (added

-

HCl)



red

solution.
Volume of titrant = 6,0 ml
Colorless solution  (added
MO)  yellow solution
(added

b. Titration II

-

HCl)



red

solution.
Volume of titrant = 5,5 ml
Colorless solution  (added
MO)  yellow solution

2

(added
c. Titration III

HCl)



red

solution.
Volume of titrant = 6,0 ml

Mixture

determination

of

-

Colorless solution  (added

carbonate and bicarbonate :

BaCl2 10 %)  turbid

25 ml solution of mixture

solution (filtered) (added

sample into 3 Erlemeyer  did

MO)  yellow solution

titration with HCl as standard

(added

solution (added 3 drops of MO
indicator previously).
a. Titration I

-

HCl)



red

solution.
Volume of titrant = 43,1 ml
Colorless solution  (added
BaCl2 10 %)  turbid
solution (filtered) (added
MO)  yellow solution
(added

-

HCl)



red

solution.
Volume of titrant = 44,5 ml
Colorless solution  (added
BaCl2 10 %)  turbid

b. Titration II

solution (filtered) (added
MO)  yellow solution
(added
-

c. Titration III

HCl)



red

solution.
Volume of titrant = 45,0 ml

G. ANALYSIS DATA
1. Standardization of HCl solution.
-

titrat volume (average) as V2 :
6,00 ml +5,50 ml+6,00 ml
3

V2 =

V2 = 5,83 ml
Known :
V1

= 25,00 ml

W

= 0,4035 g = 403,5 mg

MW

= 381,0 mg mole

V2

= 5,83 ml

Asked :
N HCl = …?
Solution :
N HCl =

V1
eq
W
X2
X
100,0
mmole MW
V2

N HCl =

25,00 ml
eq
403,5 mg
X2
X
100,0
mmole 381,0 mg /mmole
5,83 ml

N HCl =

0,2500ml X 2

eq
X 1,059 mmole
mmole
5,83 ml

N HCl = 0,09082 N
2. Mixture determination of carbonate and bicarbonate
-

Titrant volume (average) as V1 :
V1
V1

-

=

50,50 ml +50,20 ml+ 49,60 ml
3

= 50,10 ml

Titrant volume (average) as V2 :

43,00 ml+ 44,50 ml+ 45,00ml
3

V2

=

V2

= 44,20 ml

Known :
V1

: 50,10 ml

V2

: 44,20 ml

N HCl

: 0,09082 N

Asked

:

a) Amount of CO3-

b) amount of HCO3-

Solution :
a) CO3-

=

(V 1−V 2 ) X NHCl
2 X 25,00ml

CO3-

=

(50,10−44,20 ) ml X 0,09082 N
2 X 25,00 ml

CO3-

= 0,01072 N ~ 0,01072 mmole/ml

b) HCO3-=
HCO3-=

V 2 X NHCl
25,00 ml
44,20 ml X 0,09082 N
25,00 ml

HCO3-= 0,7168 N ~ 0,7168 mmole/ml
H. DISCUSSION
Titrimetry method known as volumetric method that was analysis
quantitative that was basicly on stoichiometry of chemical reaction between
analyte and titrant component. Titrant was added in analyte solution until
reach certain amount until reach equivalent point. In titrimetry experiment
was done 2 activity, that are:
1. Standardization of HCl solution.
Because of standard solution of HCl is not primary standard solution,
so it was need to do standardization. HCl solution known as secondary
standard solution because its concentration easy to change / not constant in the

saving it was can happen from HCl properties that was hydroscopic, it means
can adsorb water vapor that was there on its area, so the water that was bound
will change its concentration and it was not constant in its saving. The aim to
do standardization is for know the concentration of HCl as certain using of
sodium tetraborax bicarbonate (Na2B4O7.10H2O), because it was primary
standard. sodium tetraborax bicarbonate solution was used because has
constant concentration and constant in its saving also reacted as fast with HCl.
Beside of that, sodium tetraborax bicarbonate that was weak base able to
reacted with chloride acid. Its reaction :
Na2B4O7.10H2O (l) + 2HCl(l)  2NaCl(l) + 4 H3BO3(l) + 5H2O(aq)
After done the standardization then we done titration with observation
of equivalent point also end point of titration, because all of that has relation.
Sodium tetraborax bicarbonate was reacted with MO indicator in that problem
indicator used for given mark when titration had been finished (determination
of end point titration) also identification product from its mixture of solution.
Titration is chemical analysis that was fast and accurate so it was certain to
used for determination amount of component or substance in a solution. MO
indicator given color in analyte and titration was done until 3 times with
calculate volume average of titrant so we can knew the concentration of HCl
solution standard. HCl solution was done as titrant. After done titration we
gotten analyte color (sodium tetraborax bicarbonate) become red, that was
mark that it was reach a equivalent point (amount of acid mole that was added
same with the amount of base mole). MO indicator has section of pH = 3,1 –
4,4 that was acid properties from reaction that was done it is borax (H 3BO3).
From titration that was done until 3 times so we got average volume of titrant
is 5,83 ml so we gotten normality of HCl solution is 0.09082 N.
2. Determination of Mixture Carbonate and Bicarbonate.

Sample solution of carbonate and bicarbonate were reacted wit MO
indicator that was resulted yellow color then done titration with chloride acid
standard (HCl) so resulted red color. Titration about 3 times done for got the
result (amount of carbonate) that more accurate. We gotten HCl volume about
50,5 ml, 50,2 ml, and 49,6 ml. so the average volume as 50,1 ml with
carbonate amount as 0,01072 mmole/ml.
Determination of bicarbonate was done with reacted sample solution
and several drops of barium (II) chloride 10 (BaCl2). After adding of BaCl2 10
% we gotten solution color become turbid also formed white precipitate.
Adding of BaCl210 % has function for precipitate carbonate ion (CO 3-) so in
sample solution just there in bicarbonate ion. Reaction between BaCl 2 10 %
an carbonate ion will form BaCO 3 precipitate then it was filtered for
separating precipitate and sample solution (bicarbonate). Sample solution then
added with MO indicator for given mark mark (color change) when end
titration (determination of end point titration) also identification product from
mixture solution, then gotten the color of sample solution become yellow.
Titration done 3 times with using chloride acid solution (HCl) resulted color
o0f solution become red. Finally the volume of titrant that was gotten are 43,1
ml, 44,5 ml, and 45,0 ml so the average volume of titrant is 44,2 ml with
carbonate amount 0,1768 mmole/ml. the reaction is :
BaCl2 (l) + CO3-(l)  BaCO3 (s) ↓

+ 2 Cl-(l)

HCO2(l) + HCl (l)  H2CO3(l) + Cl-(l)

I. CONCLUSION
According to experiment, we may conclude that :
1. Standardization of HCl solution ha sbeen getting the normality is 0,09082
N

2. Determination of carbonate and bicarbonate have been getting each
amount are 0,01072 mmole/ml and 0,1768 mmole/ml, respectively
J. SUGGESTION
1. Apperentice should pay attention with significant number in every
apparatus needed so that calculation can be correct.
2. Apperentice and assistant should carefull in doing teamwork to get
accurate result.

BIBLIOGRAPHY
Aarelly, Kiran., et. al. (2012). Quantitative Determination of Flurbiprofen In Both
Bulk And Formation Using Acid-Base Titration. International Journal Of

Pharmacy. (online). Vol. 2 no. 4 page 765. (accessed on November 10 th,
2014).
Angelova, R., et.al. (2007). Comparative Study of Titrimetric Methods For
Determination of Organic Carbon In Soils, Compost, And Sludge. Journal of
International Scientific Publications : Ecology anf Savety. (online). Vol. 8.
Page 437 (accessed on November 10th , 2014)
Harvey, David. 2000. Modern Analytical Chemistry. USA : DePauw University
John. 2001. Basic of Titration. USA : Cambridge University
Kealey, D., et. al. 2005. Instant Note Analytical Chemistry. UK : University of Leeds
Tim Dosen. 2014. Penuntun Praktikum Kimia AnalitikI. Makassar :UNM
Vogel., et. al. 1989. Testbook of Quantitative Chemical Analysis. UK : Longman
Group

APPROVAL SHEET

The complete report of Analytical Chemistry I with the tittle “Titrimetry” that
was made by :
Group : II (two)
Class : ICP B Chemistry
This has been checked and consulted by assistant and assistant coordinator, so this
report is accepted.
Makassar, January 2015
Assistant coordinator,

Assistant,

(Lukmanul Hakim S)

(Lukmanul Hakim S)
Known by
responsibility Lecturer,

Sulfikar, S.Si. M.T
197012021988022006