Determination of Aluminium with Potentiometric Method

Determination of Aluminium with Potentiometric Method

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

Reagents
c(HCl) = 1 mol/L; D0
c(NaOH) = 1 mol/L; D1
w(KF) = 0.10 (10%); D2

Sample
a sample with 40...50 mg Al content
50 mL dist. water
5 mL w(sodium gluconate) = 0.25 (25%)

Remarks
Determination reaction:

Al(OH)3 + 6 KF K3AlF6 + 3 OH-

Calculations:

Aluminum=(C70+C71)*C01*C02*C03/C04/C00;3;%

Aluminum = content of Al in %

C01 = concentration of titrating agent (1 mol/L)

C02 = molecular mass / “normality“ (26.982 / 3 = 8.994)

C03 = factor for % (100)

C04 = factor for mL L (1000)

C70 = excess of the method “Al 2“ (stop V - EP1)

C71 = consumption in method “Al 4“ (EP1)

Answer

Literature

Metrohm Application Bulletin No. 24: Potentiometric determination of aluminium

Method documentation

'pa

751 GPD Titrino 15215 751.0010

TIP Aluminum

parameters

>sequence

1.stirrer: …ON

2.method: …Al 1

3.method: …Al 2

4.method:… Al 3

5.pause …180 s

6.method: …Al 4

>statistics

status: …OFF

>preselections

req.ident:… OFF

req.smpl size:… value

meas.mode: …pH

meas.input: ….1

temperature …25.0 °C

------------

'fm

751 GPD Titrino 15215 751.0010

TIP Aluminum

>calculations

Aluminum=(C70+C71)*C01*C02*C03/C04/C00;3;%

C00= 0.2986

C01= 1

C02= 8.994

C03= 100

C04= 1000

C70= 0.193

C71= 2.684

------------

'fr

751 GPD Titrino 15215 751.0010

TIP Aluminum

smpl size …0.2986 g

C70 ….0.193

C71 …..2.684

Aluminum….. 8.666 %

TIP terminated

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