wtw PhotoLab Spektral Operating Instructions Manual page 22

Instructions for the Preparation of Standard Solutions
Standard solution of acid capacity
Preparation of a standard solution:
A sodium hydroxide solution of 0.1 mol/l
(corresponds to 100 mmol/l) is used.
Further investigational concentrations may be
prepared from this stock solution by diluting
accordingly.
Stability:
When stored in a cool place (refrigerator), the
diluted investigational solutions remain stable
for one week.
Reagents required:
1.09141.1000 Sodium hydroxide solution
0.1 mol/l
1.16754.9010 Water GR for analysis
XX
Standard solution of bromine
acc. to DIN EN ISO 7393
Preparation of a KlO
3
Dissolve 1.005 g of KlO
water in a calibrated or conformity-checked
1000-ml volumetric flask. Subsequently make up
to the mark with distilled water.
Preparation of a KlO /Kl standard solution:
3
Transfer 8.90 ml of the KlO
calibrated or conformity-checked 1000-ml
volumetric flask, add approx. 1g of Kl and make
up to the mark with distilled water.
1 ml of this solution is equivalent to 0.020 mg
of bromine.
Preparation of the bromine standard solution:
Pipette 10 ml KlO /Kl standard solution into a
3
calibrated or conformity-checked 100-ml
volumetric flask, add 2.0 ml of H
leave to stand for 1 min, and then add NaOH 2
mol/l dropwise (approx. 1 ml) until the solution
just loses its colour. Subsequently make up the
solution to the mark with distilled water.
The concentration of the solution is 2.00 mg/l
bromine.
Stability:
The KlO stock solution remains stable for 4
3
weeks when stored in a cool place. The KlO
standard solution can be used for 5 hours when
stored in a cool place. The dilute bromine
standard solution is not stable and must be used
immediately.
Reagents required:
1.02404.0100 Potassium iodate, volum. standard
1.05043.0250 Potassium iodide GR for analysis
1.09072.1000 Sulfuric acid 0.5 mol/l
1.09136.1000 Sodium hydroxide solution 2 mol/l
1.16754.9010 Water GR for analysis
stock solution:
in 250 ml of distilled
3
stock solution to a
3
SO 0.5 mol/l,
2 4
/Kl
3
Release 05/04