- Lead carbonate which is used as a pigment....
Tuesday, April 27, 2010
Friday, April 23, 2010
Phenol route is widely used for the production of paracetamol why?
- Simple process, easy or less hazardous
- No pressure reactor required
- No addition of metallic impurity like iron
- Cheap
- Better quality product
- Paracetamol obtained by phenol route are of good quality & purely white crystals.
What are the important things to be noted while conducting the production of paracetamol from phenol?
- Isolation of sections & thorough cleaning & isolation of p-amino phenol is very important.
- Exposure to long timings & duration decomposes the product, especially p-amino phenol.
- Provision of a generator is essential due to critical nature of reaction & also no time can be lost to power breakdown etc.
Identification Test (4) For Paracetamol
- Dissolve 0.2gm paracetamol in 4ml pyridine.
- Add 0.5gm of 4 nitrobenzoyl chloride, boil for 2 or 3 minutes,cool & pour into 40ml water & stirr.
- The ppt after washing with 30ml water, 30ml of 1% W/V solution of sodium carbonate & 30ml water & recrystallisation from alcohol, melts at 210 degree.
Identification Test (3) For Paracetamol
- Boil 0.1gm paracetamol with 1ml HCl for 3 minutes.
- Add 10ml water & cool, no ppt produced.
- Add 0.05ml of 0.1N potassium dichromate, a violet colour slowly develops, which donot become red.( distinction from phenacetin).
Identification Test (2) For Paracetamol
- Dissolve 50mg paracetamol in 100ml methyl alcohol .
- Mix 1ml of the solution with 1ml 0.1N HCl & sufficient methyl alcohol to produce 100ml, extinction of 1cm layer of resulting solution at maximum of 249nm about 0.44
Identification Test (1) For Paracetamol
- Dissolve 0.1gm paracetamol in 10ml water .
- Add 0.05ml ferric chloride solution.
- A violet blue colour is produced.
According to IPS, give the solubility of paracetamol
- Sparingly soluble in water, freely soluble in alcohol, soluble in acetone & in solution of alkali hydroxide.
According to IPS, give a description about paracetamol?
- White crystals or white crystalline powder, odourless, taste -slightly bitter.
According to Indian Pharmaceutical Specifications,what is the dose of paracetamol?
- 0.5 to 1gm, up to 4gm daily, in divided doses.
What is the use of antipyretics?
- In the case of fever antipyretics lower body temperature often as a result of inducing perspiration.
Monday, April 5, 2010
Which type of the process is usually done in the lab for determining VFA test?
- Microsale total recovery steam distillation
What is the function of non volatile fatty acid?
- To increase the stability by virtue of their surface activity.
What is the function of volatile fattyacid?
- To reduce the stability of latex by increasing the ionic strength of the serum.
What is the purpose of adding HCHO to natural rubber latex?
- To reduce the ammonia content to a certain level.
Small filter papers are fastened over the ends of the centrifuging tubes in sludge determination.why?
- To prevent excessive evaporation of water & the possible formation of a surface skin.
What are the chief impurities of natural rubber latex?
- Dirt, sand,bark fragments & Magnesium ammonium phosphate
What is the importance of sludge?
- It refers to non polymer impurities which tend to sediment under the influence of gravity.
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