Determination of Oxidizability of Waste Water with Potentiometric Method

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0431.100 Pt Titrode; input 1

Reagents
c(1/5KMnO4) = 0.01 mol/L; D0

Sample
25 mL waste water
5 mL w(H2SO4) = 0.35 (35%)
75 mL dist. water
15 mL c(1/5KMnO4) = 0.01 mol/L
15 mL c(1/2Oxalic acid) = 0.01 mol/L

Remarks
· Prepare sample as follows:
Add 75 mL dist. water and 5 mL w(H2SO4) = 0.35 (35%) to 25 mL of sample and heat up to a boiling mixture.

Add 15.00 mL of c(1/5KMnO4) = 0.01 mol/L and keep boiling for 10 minutes. Then add 15 mL c(1/2Oxalic acid) =0.01 mol/L.
Titrate with c(1/5KMnO4) = 0.01 mol/L according to parameters.

· Calculations:

Oxidiza.=EP1*C01*C02/C00;3;mg/L

Oxidiza. = oxidizability in mg/L permanganate consumption
C01 = molecular mass of KMnO4 * concentration of titrating agent / normality (158 * 0.01 / 5 = 0.316 g/L)
C02 = conversion g Þ mg for result expression in mg/L KMnO4 (1000)

. Answer

Oxidiza = 3.682 x 0.316 x 1000 / 25 = 46.540 mg/L

Literature
· Deutsche Einheitsverfahren zur Wasseruntersuchung Kapitel H4, Abschnitt 1

Penentuan kesadahan total dg alat potensiometer, Titrino / Titroprocessor with Potentiometric Method

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0239.100 combined pH glass electrode; input 2
6.0504.100 Ca2+ sensitive indicator electrode; input 1 reference system used from 6.0239.100

Pereaksi

c(Na2EDTA) = 0.05 mol/L in c(KOH) = 0.1 mol/L; D0
c(HCl) = 0.1 mol/L; D1
c(Acetylacetone) = 0.1 mol/L in c(Trishydroxy methylaminomethane) = 0.1 mol/L (auxiliary complexing agent, pH app. 8.5); D2

Sample
100 mL water

Remarks
· Method p+m val.
Values for the acid capacity of water.
p value = value of Phenolphthalein
m value = value of Methyl orange
The method can also be used just for p+m values, see Application 2-3.
· Method Ca-Mg:
1st break: Ca2+
2nd break: Mg2+
The method can also be used just for Ca/Mg determinations, see Application 1-7.

· Calculations:

p value=C71;2;mmol/l
m value=C72;2;mmol/l
Ca++=C73*C01*C02/C00;2;mmol/l
Mg++=(C74-C73)*C01*C02/C00;2;mmol/l
Total=C74*C01*C02/C00;2;mmol/l

p value = p value in mmol/L (if 0.00 mmol/L, the water has an initial pH below 8.2)
m value = m value in mmol/L (acid-binding-capability)
Ca++ = calcium hardness in mmol/L
Mg++ = magnesium hardness in mmol/L
Total = total hardness in mmol/L
C01 = concentration of titrating agent (0.05 mol/L)
C02 = factor for conversion for mol Þ mmol (1000)
C70 = initial pH of sample (p+m val.) = 7.75
C71 = EP1 at pH 8.2 (p+m val.) = 0.00
C72 = EP2 at pH 4.3 (p+m val.) = 5.69
C73 = EP1 from Ca2+ (Ca-Mg) = 4.471
C74 = EP2 from Mg2+ (Ca-Mg) = 6.055

. Answer

P value = 0.00 mmol/L
M value = 5.69 mmol/L
Ca++ = 4.471 x 0.05 x 1000 / 100 = 2.24 mmol/L
Mg++ = (6.055-4.471) x 0.05 x 1000 / 100 = 0.79 mmol/L
Total = 6.055 x 0.05 x 1000 / 100 = 3.03 mmol/L


· Electrode preparation:
Ca electrodes should be conditioned for 10 min. in c(CaCl2) = 0.01 mol/L before use.
· The volume of the auxiliary reagent can be optimised for the
magnesium content. Rule of thumb: Ratio Mg/Acetylacetone app. 0.05.


Literature
· Metrohm Application Bulletin No. 125: Complexometric simultaneous determination of calcium and magnesium in water samples and beverages with the aid of an ion-selective calcium electrode

Determination of p and m Value with Potentiometric Method

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0239.100 combined pH glass electrode; input 2

Reagents
c(HCl) = 0.1 mol/L; D1

Sample
100 mL tap water

Remarks
· Values for the acid capacity of water.
p value = value of Phenolphthalein
m value = value of Methyl orange

· Calculations:

p value=EP1*C01;2;mmol/l
m value=EP2*C01;2;mmol/l

p value = p value in mmol/L (if 0.00 mmol/L, the water has an initial pH below 8.2)
m value = m value in mmol/L
C01= titer of titrating agent (1.0)

p value= 0.00 mmol/l
m value=5.653 x1.0 = 5.65 mmol/l

EP1 = 0.00 mL
EP2 = 5.653 mL

· The dosing unit is external D1. This method can therefore be used directly in the TIP „Hardness“ (Application 2-4), an automated water analysis method.
· Calibrate the electrode for the SET titration.
· For automatic curve output add in , >report “curve“.

Literature
· DIN 38 409, Teil 7 (19)

Analisis kloridadlm air dg alat potensiometer, Titrino/Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode amalgamated; input 1

Reagents
c(AgNO3) = 0.01 mol/L; D0

Sample
100 mL tap water
0.5 mL c(HNO3) = 2 mol/L

Remarks
. Calculations:

Chloride=EP1*C01*C02*C03/C00;2;ppm

Chloride = fraction of chloride in ppm
C01 = concentration of titrating agent (0.01 mol/L)
C02 = molecular mass of Cl- (35.45 g/mol)
C03 = factor for ppm (1000)

. Answer

Chloride = 1.533 x 0.01 x 35.45 x 1000 / 100 = 5.43 ppm

EP1 = 1.533 mL
C00 = 100 mL

Literature

Metrohm Application Bulletin No. 130: Chloride titrations with
potentiometric end-point indication.

Analisis asam boraks dg alat potensiometer, titrino / Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0232.100 combined pH glass electrode; input 1

Pereaksi
c(NaOH) = 0.1 mol/L; D0

Sample
5.00 mL c(H3BO3) = 0.1 mol/L
10 mL d-mannitol solution, saturated
40 mL dist. Water

Remarks

· Determination reaction:
Boric acid forms an ester with mannitol:
HO-CH HC-O O-CH -
H3BO3 + 2 → B H+ + 3 H2O
HO-CH HC-O O-CH

H3BO3+2H4C2O2 →( H4C4BO4 ) - H ++ 3 H2O

· Calculations:

Bor=EP1*C01*C02*C37/C00;1;mg/l

Bor = content of Bor in mg/L
C01 = bor equivalent (1.081 mg/mL titrating agent)
C02 = factor for the conversion mL Þ L (1000)
C37 = titer of titrating agent (1.0013)
· d-mannitol solution, saturated:
App. 200 g d-mannitol dissolved in dist. water.

. Answer

Bor = 4.719 x 1.081 x 1000 x 1.0013 / 5.0 = 1021.6 mg/L

EP1 = 4.719 mL
C00 = 5.0 mL

Literature
· Metrohm Application Bulletin No. 66: Potentiometric
determination of boric acid.

Analisis Klorida di dlm air dg alat Titrino / Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode; input 1

Reagents
c(AgNO3) = 0.1 mol/L; D0

Sample
5 mL c(NaCl) = 0.1 mol/L
2 mL c(HNO3) = 2 mol/L
40 mL dist. Water

Remarks
· Calculations:

Chloride=EP1*C01*C02*C03/C00;2;%
NaCl=EP1*C01*C04/C00;2;g/l

Chloride = content of chloride in %
NaCl = content of NaCl in g/L
C01 = concentration of titrating agent (0.1 mol/L)
C02 = molecular mass of Cl- (35.45 g/mol)
C03 = factor for % (0.1)
C04 = molecular mass of NaCl (58.44)
· Select the appropriate formula. The other may be deleted. Or change the formula according to your application.

. Answer

Chloride=4.969x0.1x35.45x0.1/5=0.35%
NaCl=4.969x0.1x58.44/5=5.81 g/L

EP1=4.969 mL
C00=5.000 mL

Literature
· Metrohm Application Bulletin No. 130: Chloride titrations with potentiometric end-point indication

Analisis besi (Fe II) dg alat Titrino / Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0431.100 Pt Titrode; input 1

Pereaksi
c(KMnO4) = 0.02 mol/L; D0
Sample
2 mL c[(NH4)2Fe(SO4)2] = 0.1 mol/L, acidic solution
10 mL c(H2SO4) = 0.5 mol/L
40 mL dist. Water

Rangkuman
· Determination reaction:

5 Fe2+ + MnO4- + 8 H+ → 5 Fe3+ + Mn2+ + 4 H2O

· Calculations:

Fe++=EP1*C01*C02/C00;2;g/l

Fe++ = concentration of Fe2+ in g/L
C01 = concentration of titrating agent * titer * “normality“ (0.02 * 1.000 * 5 = 0.1)
C02 = molecular mass of Iron (55.85 g/mol)

Answer

Fe++=2.065x0.1x55.85/2=5.77 g/L

EP1=2.065 mL
C00=2.000 mL

Literature
Metrohm’s Teachware on CD-ROM

analisis iodium dg alat Titrino / Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0502.140 Cu2+ sensitive indicator electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode (KNO3 sat.)

Pereaksi
c(Na2EDTA) = 0.1 mol/L; D0

Sample
2 mL c(ZnSO4) = 0.1 mol/L
5 mL buffer pH = 10
1 mL c(CuEDTA) = 0.1 mol/L
40 mL dist. Water

Rangkuman
· Calculations:

Content=EP1*C01*C02/C00;2;g/l


Content = content of metal in g/L
C01 = concentration of titrating agent (0.1 mol/L)
C02 = molecular mass of metal (65.38 g/mol)

. Answer

Content=2.006x0.1x65.38/2=6.56 g/L

EP1=2.006 mL
C00=2.000 mL

· Buffer pH = 10:
Dissolve 54 g NH4Cl and 350 mL w(NH3) = 0.25 (25%) in dist. water and fill up to 1 litre.
· Buffer pH = 4.7:
Dissolve 123 g Na-acetate and 86 mL acetic acid in dist. water and fill up to 1 liter.
· The following metals can be determined according to this method:
buffer solution molar mass
Water, total hardness (Ca + Mg) pH = 10… 64.40
Barium Ba pH = 10… 137.36
Cadmium Cd pH = 10… 112.41
Cobalt Co pH = 10… 58.94
Nickel Ni pH = 10… 58.71
Zinc Zn pH = 10…65.38
Lead Pb pH = 4.7…207.21

Literature
· Metrohm Application Bulletin No. 101: Complexometric titrations with the Cu ISE

Analisis logam dg alat Titrino / Titroprocessor

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0502.140 Cu2+ sensitive indicator electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode (KNO3 sat.)

Reagents
c(Na2EDTA) = 0.1 mol/L; D0

Sample
2 mL c(ZnSO4) = 0.1 mol/L
5 mL buffer pH = 10
1 mL c(CuEDTA) = 0.1 mol/L
40 mL dist. Water

Remarks
· Calculations:

Content=EP1*C01*C02/C00;2;g/l

Content = content of metal in g/L
C01 = concentration of titrating agent (0.1 mol/L)
C02 = molecular mass of metal (65.38 g/mol)

. Answer

Content=2.006x0.1x65.38/2=6.56 g/L

EP1=2.006 mL
C00=2.000 mL

· Buffer pH = 10:
Dissolve 54 g NH4Cl and 350 mL w(NH3) = 0.25 (25%) in dist. water and fill up to 1 litre.
· Buffer pH = 4.7:
Dissolve 123 g Na-acetate and 86 mL acetic acid in dist. water and fill up to 1 liter.
· The following metals can be determined according to this method:
buffer solution molar mass
Water, total hardness (Ca + Mg) pH = 10… 64.40
Barium Ba pH = 10… 137.36
Cadmium Cd pH = 10… 112.41
Cobalt Co pH = 10… 58.94
Nickel Ni pH = 10… 58.71
Zinc Zn pH = 10…65.38
Lead Pb pH = 4.7…207.21

Literature
· Metrohm Application Bulletin No. 101: Complexometric titrations with the Cu ISE

Analisis calsium dg alat Titrino / titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode amalgamated; input 1

Pereaksi
c(Na2EDTA) = 0.1 mol/L; D0
Sample 2 mL c(CaCl2) = 0.1 mol/L
10 mL buffer pH = 10
40 mL dist. Water

Remarks

· Calculations:

c(Ca++)=EP1*C01/C00;3;mol/l

Ca++ = concentration of Ca2+ in mol/L
C01 = concentration of titrating agent (0.1 mol/L)

. Answer

c(Ca++) = 2.043 x 0.1/2 = 0.102mol/L

EP1=2.043 mL
C00=2.000 mL
· Coating of Ag Titrode: Clean Ag Titrode first by immersing it in conc. HNO3, then immerse it shortly in Hg.
· Buffer pH = 10: Dissolve 54 g NH4Cl and 350 mL w(NH3) = 0.25 (25%) in dist water and fill up of 1 liter. · If several metal ions which form EDTA complexes are present, their sum is determined. · For a greater break, add Hg-EDTA complex.

Literature
Metrohm’s Teachware on CD-ROM

Analisis asam oxalat dlm fasa organik dg alat Titrino / Potensiometri

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0103.100 pH glass electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode (LiCl sat. in ethanol)

Reagents
c(TBAOH) = 0.1 mol/L; D0
TBAOH = Tetrabutyl ammonium hydroxide

Sample
2 mL c(C2H2O4) = 0.1 mol/L; HOOC-COOH
25 mL ethanol

Remarks
Calculations:

Oxalic=EP2*C01/C02/C00;3;mol/l

Oxalic = concentration of oxalic acid in mol/L
C01 = concentration of titrating agent (0.1 mol/L)
C02 = factor for “normality“ (2) · Compare also titration in aqueous medium, application No. 1-4

Answer

Oxalic = 4.221 x 0.1 / 2 / 2 = 0.106 mol/L

EP1 = 2.048 mL
EP2 = 4.221 mL
C00 = 2.00 mL

Literature
Metrohm’s Teachware on CD-ROM

Analisis asam oxalat dg alat Titrino / Titroprocessor

Alat yang digunakan

Potentiometer = 751 GPD Titrino / Titroprocessor

Electrodes = 6.0232.100 combined pH glass electrode; input 1

Pereaksi

c(NaOH) = 0.1 mol/L; D0

Sampel

2 mL c(C2H2O4) = 0.1 mol/L;

HOOC-COOH pK1 = 1.42, pK2 = 4.31

50 mL dist. water

Rangkuman
Calculations:

Oxalic=EP2*C01*C37/C02/C00;3;mol/L

Oxalic = concentration of oxalic acid in mol/L

C01 = concentration of titrating agent (0.1 mol/L)

C02 = factor for “normality“ (2)

C37 = titer of titrating agent (1.0013 common variable of “Tit.NaOH“) Compare also titration in non aqueous medium, application No. 1-5 For pK determinations, the electrode should be calibrated.

Answer

Oxalic = 4.098 x 0.1 x 1.0013 / 2 / 2 = 0.103 mol/L

EP1 = 2.110 mL

EP2 = 4.098 mL

C00 = 2 mL

Literature

Metrohm’s Teachware on CD-ROM

Penentuan analisis asam kuat dg alat Titrino / Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0232.100 combined pH glass electrode; input 1

Pereaksi
c(NaOH) = 0.1 mol/L; D0

Sampel
2 mL c(HCl) = 0.1 mol/L 50 mL dist. Water

Rangkuman
Calculations:

C(acid) = EP1*C01*C37/C00 ; 3 ; mol/L

c(acid) = concentration of acid in mol/L
C01 = concentration of titrating agent (0.1 mol/L)
C37 = titer of titrating agent (1.0013 common variable of “Tit.NaOH“) Carbonate may be detected separately if present!

Answer
C(acid) = 1.996 x 0.1 x 1.003 / 2.00 = 0.100 mol/L
EP1 = 1.996 mL C00 = 2.00 mL

Literature
Metrohm’s Teachware on CD-ROM

Penentuan angka asam dg alat potensiometer

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0133.100 pH glass electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode
(LiCl sat. in ethanol)

Reagents
c(NaOH) = 0.1 mol/L; D0

Sample
app. 5-10 g sunflower oil
50 mL ethanol / diethylether (1 : 1), neutralized

Remarks
• Calculations:

Acid.No=EP1*C01/C00;2;mg/g
FFA=RS1*C02/C03;2;

Acid.No = acid number in mg KOH per g of sample
FFA = free fatty acid
C01 = mg KOH / 1 mL titrating agent (5.61)
C02 = relative molecular mass (282 for oleic acid)
C03 = factor (561)

. Answer

Acid.No = 0.150 x 5.61 / 10.3223 = 0.08 mg/g
FFA = 0.08 x 282 / 561 = 0.04

RS1 = 0.08
EP1 = 0.150 mL
C00 = 10.3223 g

Literature
• Metrohm Application Bulletin No. 141: Analysis of edible oils and fats.

Penentuan angka saponifikasi dg alat potensiometer

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0232.100 combined pH glass electrode; input 1

Pereaksi
c(HCl) = 1 mol/L; D0

Sampel
app. 2 g sunflower oil
25 mL c(KOH) = 0.5 mol/L in ethanol
app. 10-20 mL dist. water

Rangkuman
· Calculations:

Sapon.No=(C01-EP1)*C02/C00;1;mg/g

Sapon.No = saponification number in mg KOH per g of sample
C01 = consumption of blank sample (12.199 mL)
C02 = mg KOH / 1 mL titrating agent (56.1)

. Answer

Sapon.No = (12.199-5.271) x 56.1 / 2.0224 = 192.2 mg/g

EP1 = 5.271 mL
C00 = 2.0224 g

· Sample preparation:
Weigh out approx. 2 g sample in a round-bottomed flask. Add 25 mL alcoholic KOH solution plus a few boiling beads and allow to boil lightly for at least 30 min. Shake from time to time. Finally rinse the content of the round-bottomed flask into a beaker with a small quantity of dist. water and back titrate the excess of potassium hydroxide with HCl. A blank control sample should be prepared and treated identically. Enter the blank value as C01.

Literature
· Metrohm Application Bulletin No. 141: Analysis of edible oils and fats.

Penentuan angka angka Peroxide dg alat potensiometer

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0431.100 Pt Titrode; input 1

Pereaksi
c(Na2S2O3) = 0.01 mol/L; D0
Prepared daily from c = 0.1 mol/L

Sampel
app. 5 g sunflower oil
50 mL glacial acetic acid / chloroform (3 : 2)
1 mL KI saturate
100 mL dist. water

Remarks
· Calculations:

Perox.No=(EP1-C01)*C02/C00;2;meq/kg

Perox.No = peroxide number in meq.O2/kg
C01 = consumption of blank sample (0 mL)
C02 = factor (10)

. Answer

Perox.No = 0.8874 x 10 / 5.0188 = 1.77 meq/Kg

EP1 = 0.8874 mL
C00 = 5.0188 g

· Sample preparation:
Weigh out accurately 5 g sample in an Erlenmeyer flask and add 50 mL of the glacial acetic acid / chloroform mixture. Then add 1 mL of the KI solution and shake during 5 s. Now allow the mixture to stand for about 1 min. in a dark place. After this, rinse the contents of the
Erlenmeyer flask out into a beaker with 100 mL dist. water and immediately back-titrate the iodine thus liberated with sodium thiosulphate. A blank control sample should be prepared and treated in the same way. Enter the blank value as C01.
· The sample must be stirred well during the titration, in order to obtain
a good emulsion.

Literature
· Metrohm Application Bulletin No. 141: Analysis of edible oils and fats.

PENENTUAN ANALISIS KALSIUM DAN MAGNESIUM DALAM PRODUK SUSU

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor

Electrode = 6.0502.140 Cu2+ sensitive indicator electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode (KNO3 sat.)

Pereaksi
c(EGTA) = 0.1 mol/L; D0
c(Cu complex) = 0.100 mol/L; D1
Buffer solution pH = 10; D2

Sampel
app. 10 g milk

Remarks
· Calculations:

Calcium=C70*C01*C02*C03/C00;3;%

Calcium = content of calcium in %
C01 = concentration of titrating agent (0.1 mol/L)
C02 = molecular mass of calcium (40.08 g/mol)
C03 = factor for % (0.1)
C70 = EP1 from submethod Milk-Ca3

. Answer

Calcium = 3.008 x 0.1 x 40.08 x 0.1 / 10.0516 = 0.12%

C70 = 3.008

· Reagents:
c(EGTA) = 0.100 mol/L:
38.04 g EGTA - ethylene glycol-0,0’-bis-(2-aminoethyl)-N,N,N’,N’-tetraacetic acid are added to a 1 liter volumetric flask, dissolved in 250 mL c(NaOH) = 1 mol/L and the solution made up to the mark with dist. water.

Cu complex:
EGTA titrant (100 mL) is mixed with 100 mL of a solution containing 0.2 mol/L NH4Cl and exactly 0.100 mol/L Cu(II)nitrate. Titration can used to check that this solution contains no excess of Cu(II) or EGTA.

Buffer solution pH = 10:
54 g NH4Cl is dissolved in ca. 400 mL dist. water in a volumetric flask, 300 mL w(NH3) = 0.25 (25%) added and the solution made up to 1 liter with dist. water.

· The method „Milk-Ca3“ can also be used as work-alone method
(without TIP). Add the Cu complex-solution and the buffer solution
manually.

Literature
· Metrohm Application Bulletin No. 235: Potentiometric titration of Ca
(Mg) in milk products

Penentuan Formaldehyde Number di dalam jus buah dg alat potensiometer

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0232.100 combined pH glass electrode; input 1

Pereaksi
c(NaOH) = 0.1 mol/L; D0
w(HCHO) = 0.35 (35%), adjusted to pH = 8.5 with NaOH; D1

Sampel
25 mL sample (orange juice)

Electrodes
6.0232.100 combined pH glass electrode; input 1

Remarks
• Determination reaction:
OH
H2C=O + H2N-R Þ H2C + H+
NHR
Amino groups of amino acid react according to the above reaction.

• Calculations:

Formol No = C70*C01;1;

Formol No = formol number as mL NaOH 0.1 mol/L for 100 mLsample solution
C01 = factor for 100 mL sample solution (4)
• Calibrate the electrode for the SET titration.

. Answer

Formol No = 5.634 x 4 = 22.5

C70 = 5.634

Literature
• Metrohm Application Bulletin No. 180: Automatic determination of the
formol number in fruit and vegetable juices

Analisis garam di dalam kaldu

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode amalgamated; input 1

Reagents
c(AgNO3) = 0.1 mol/L; D0

Sample
20 mL sample solution
5 mL c(HNO3) = 2 mol/L
30 mL dist. Water

Remarks
• Calculations:

NaCl=EP1*C01*C02*C03/C00;2;%

NaCl = content of NaCl in broth in %
C00 = sample size (10 g / 100 = 0.1 g)
C01 = molecular mass of NaCl (58.44 g/mol)
C02 = concentration of titrating agent (0.1 mol/L)
C03 = factor for conversion mL Þ L and for % (0.001*100 = 0.1)

. Answer

NaCl = 8.070 x 58.44 x 0.1 x 0.1 / 0.1 = 47.16 %

EP1 = 8.070 mL
C00 = 0.1 g

• Sample preparation:
Dissolve 10 g (1 cube) conc. broth in 800 mL boiling dist. water. Rinse this solution in a 2000 mL measuring flask. Allow to cool down and fill up to the mark. Filter with a folded filter. Take 20 mL aliquots.

Literature
• Metrohm Application Bulletin No. 130: Chloride titrations with potentiometric end-point indication.