Karl Fischer Titration :-
Karl-fischer titration is method to use to determine amount of water content and moisture content in given sample.
Karl-fischer titration is based on an iodine/iodide reaction means water is react with iodine.
The apparatus consists of an automatic burette, a back titration flask, a stirrer , and an equipment for amperometric titration at constant voltage or potentiometric titration at constant current.
Because water determination is extremely hygroscopic the titration apparatus should be protected from atmospheric moisture.
Silica gel or calcium chloride for water determination is usually used for moisture protection.
PREPARATION OF KFR REAGENT :-
- Take 400 ml methanol and 80 mg pyridine and keep this solution in freezi bath.
- Supply sulfar dioxide ( SO2) in this solution till weight is increase in 20 gm.
- After add 45 g iodine and dissolved it and kept this solution for 24 hrs.
- Now days we are replaced pyridine to imdiazole.
- First we injected sample in chamber.
- After we add KFR REAGENT .
- When KFR REAGENT and sample are starting reaction if water is present current flow is increases.
- factor 1ml OF KFR = 3.5 mg water.
- End point is detected when electric current is stable and Not increase.
- Wear a mask and gloves when handling Karl Fischer reagents.
- Take care to avoid spillage.
- Avoid inhaling reagents and avoid skin contact.
- If a reagent comes into contact with your hands, wash the area with soap and rinse with ample water.
- If you feel unwell after inhaling fumes, rest quietly in a location with clean air.
- If a reagent splashes into your eyes, wash them with clean water for least 10 minutes and then consult your physician.
- If working clothes are contaminated, remove the cloths as soon as possible.
- If reagents are spilled, dispose of them after spreading sand or a similar material over the affected area.
1. Which method is used to determination of water content ?
A. Kjeldahl method
B. Karl-fischer titration
C. Diazotization titration
D. All of the above
2. How many gm iodine is used in KFR REAGENT ?
3. 1 ml of KRF =
A. 2.4 gm water
B. 3.6 gm water
C. 3.5 mg water
D. 1.4 mg water
4. Which material are used as moisture protection?
A. Calcium chloride
B. Silica gel
C. A and B
D. None of this
5. Karl fischer titration working principal is?
A. Iodine reaction
B. Iodide reaction
C. A and B
D. None of the above