Chloride Titrations in Tap Water with Potentiometric end-point indication

Chloride Titrations in Tap Water with Potentiometric end-point indication

Equipment
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.

Method documentation

'pa

751 GPD Titrino 15215 751.0010

DET U Chloride

parameters

>titration parameters

meas.pt.density… 4

min.incr. …10.0 ml

dos.rate max…. ml/min

signal drift …50 mV/min

equilibr.time …26 s

start V:… OFF

pause …0 s

dos.element:… internal D0

meas.input: …1

temperature… 25.0 °C

>stop conditions

stop V: …abs.

stop V …99.99 ml

stop U …OFF mV

stop EP …1

filling rate max…. ml/min

>statistics

status: …OFF

>evaluation

EPC …5

EP recognition:… all

fix EP1 at U …OFF mV

pK/HNP: …OFF

>preselections

req.ident: …OFF

req.smpl size:… OFF

activate pulse: ….OFF

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'fm

751 GPD Titrino 15215 751.0010

DET U…. Chloride

>calculations

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

C00= 100

C01= 0.01

C02= 35.45

C03= 1000

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'fr

751 GPD Titrino 15215 751.0010

U(init) 17 mV DET U Chloride

smpl size….. 100 ml

EP1… 1.533 ml… -38 mV

Chloride… 5.43 ppm

stop EP reached

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'cu

751 GPD Titrino 15215 751.0010

start V 0.000 ml DET U Chloride

1.0 ml/div dU=20.0 mV/div

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