Gujarat Technological University 2010 B.Pharm Pharmaceutical Analysis – I - Question Paper

Q.1 (a) Enumerate areas of application of acid-base buffers. Derive
Henderson-Hasselbach formula for finding pH of buffer solution.
06
(b) compute pH of solution resulting by mixing 50 ml 0.2N NaOH and
50 ml 0.4 N CH3COOH, pKa of Acetic acid is 4.76.
05
(c) I. Why is phenolphthalein colorless beneath pH 8.3 and above
pH 13?
II. Acetic acid is a leveling solvent as well as differentiating
solvent.
05
Q.2 (a) What is hydrolysis? Derive formula for finding pH of aqueous
solution of salt of weak acid and strong base.
06
(b) compute pH and degree of hydrolysis in 0.1 M Ammonium
chloride solution. Kb is 1.8 X 10-5.
05
(c) Write note on composition and standardization of Karl Fischer
Reagent? provide reaction involved in the Karl Fischer Reagent.
05
Q.3 (a) Write a note on estimation of Nitrogen in organic compounds by
Kjeldhal method.
06
(b) 25ml of 0.1M Acetic acid is titrated with 0.1N NaOH. compute the
pH of the solution when quantity of NaOH is added. (Ka is 1.82 x 10-
5)
I. 0.0 ML
II. five ML
III. 25 ML
IV. 30 ML
05
(c) I. Write a short note on ionic product of water.
II. discuss the term: Precision, Accuracy and LOD.
05
Q.4 (a) discuss theroy of multiple solvent extrations. 06
(b) A 20 aliquot of 0.4% w/v aqueous solution of acetanilide was
extracted with (I) 30 ml ether (II) 3 times with 40 ml portion of
ether. The ether/water partition co-efficient for acetanilide is 3.0.
compute total amount of drug extracted in every case?
05
(c) I. How the pH will affect the extractability of drugs.
II. What is difference ranging from QA and QC?
05
Q.5 (a) Write a note on Diazotization nitrite titration. 06
(b) Write a note on Iodometric titration. 05
(c) I. Equivalent weight of KMnO4 modifications with the media.
II. describe the solvent used in non aqueous titration.
05
Q. six (a) kinds of complexometric titrations. Masking and damasking of
complexometric titration.
06
(b) discuss importance of von-Weimar ratio, co-precipitation and postprecipitation
in gravimetric method of estimation.
05
(c) pM Indicator 05
Q.7 (a) discuss the term solubility product constant. explain applications of
solubility product principle in analysis.
06
(b) Write a note on the determination of halogen by Volhards' method. 05
(c) Classify sources of analytical errors. How can they be minimized. 05

Earning:   Approval pending.