Guru Nanak Dev University 2007-3rd Sem B.Sc Chemistry BASIC ANALYTICAL (Chem-304) (, 2k7) - Question Paper

2117

B.Sc. (Hons. School) Chemistry III-Semester

CHEMISTRY

Paper - CHEM-304

(Basic Analytical Chemistry)

Time allowed : 3 Hours
Maximum Marks : 100


part - A
(2 x 10 = 20)
All ques. are compulsory. every ques. carries two Marks.

1. describe the term confidence limit and coefficient of variation.

2. What is the significance of accuracy and precision in quantitative analysis ?

3. What is the effect of pH on the solubility of a precipitate ?

4. provide block diagram of sampling stages.

5. Write about stoichiometric computations in chemical analysis.

6. discuss the principle governing the separation by extraction. What is distribution coefficient ?

7. elaborate indicator and reference electrodes ? provide 1 example of every electrode.

8. Write about significant figures and computational rules.

9. What is the role of pH in complexometric titrations ?

10. describe formal potential and redox potential.


part - B

Attempt any 8 ques..
All ques. carry 5½ marks.

1. discuss and illustrate different tests of significance. discuss clearly the meaning of a 95% and 99% confidence interval of the mean. (5½)

2. explain briefly the significance of the subsequent in the statistical treatment of analytical data :
(i) Confidence Limit
(ii) Method of lowest square ( two + 3½ )

3. discuss and illustrate stoichiometric computations in titrimetric and gravimetric analysis. (5½)

4. discuss the meaning of the subsequent terms :
(i) electrical double layer,
(ii) lyophillic colloids,
(iii) coagulation,
(iv) peptization and
(v) curdy precipitation (5½)

5. elaborate the factors which influence the particle size? What is the effect of diverse ion and common ion on the solubility of a precipitate ? (5½)

6. (a) explain the criteria of selecting a suitable acid-base indicator. provide a brief account of different acid-base indicators.
(b) Write short note on glass electrode. (3½ + 2)

7. (a) explain the theory of potentiometric titrations as applied to a redox reaction.
(b) discuss why the pH of a solution is an important factor in the selection of a metallochromic indicator. (3½ + 2)

8. explain briefly ion-sensitive and membrane electrodes. (5½)

9. explain multiple and counter-current extraction. discuss why multistep extraction is more economical than a single step extraction ? What do you mean by solvent extyraction by flow injection analysis ? (5½)

10. elaborate complexation reagents ? Write structural formulae of 2 complexation reagents used in complexometric titrations. Also write the structures of their complexes with metal ions. (5½)

11. define the principles of volumetric and gravimetric analysis. elaborate the advantages of former over the latter ? (5½)

12. Write short notes on the subsequent :
(i) Differentiating and levelling solvents
(ii) Redox potential and liquid junction potential. (2½ + 3)


part - C

Attempt any 2 ques.
every ques. carries 18 Marks.

1. (a) define the statistical criteria of good sampling. What factors need to be considered for good sampling plan ? Disuss sampling procedure for solid and liquid samples.
(b) Comment, precision is no guarantee of accuracy. (13 + 5)

2. (a) discuss the conditions which a provided precipitation reaction must satisfy to be used in titrimetric analysis. explain the principle of thiocyanate method for determination of silver.
(b) define the pH limitations of ion-sensitive electrodes. (13 + 5)

3. Write short notes on the subsequent :
(a) Physiological buffers
(b) Solid phase extraction
(c) Multiple batch extraction (6 x 3)

4. discuss the difference ranging from determinate and indeterminate errors. Point out the causes of these errors and their effects on the outcomes of analysis. What is the importance of control charts ? (18)

Earning:   Approval pending.