CHEM-323

Chapter 19- Potentiometric Techniques

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1. Select the suitable working electrode in the polarography for oxidation study

  1. Pt
  2. C
  3. Hg
  4. All of the above

2. Three main sequence (steps) involved in the Stripping Voltammetry are

  1. Metal ion deposition, stop the sample agitation and scanning
  2. Scanning, metal deposition and sample agitation of the solution
  3. Sample agitation of the solution and scanning of the electrode
  4. Stop the agitation, metal ion deposition and scanning

3. E1/2 in the graph represents (see figure)

  1. Half reduction potential of the analtye
  2. Reduction potential of the analyte
  3. Residual potential of the analtye
  4. Limiting potential of the analyte

4. In Coulometry anlatyes are

  1. Measured at equilibrium
  2. Measured at exhaustively
  3. Measured at non quantitative conditions
  4. Measured as qualitative approach

5. Nonfaradic Current is related to

A. Current other than oxidation and reduction

B. Current produced due to oxidation

C. Current produced due to reduction

D. None of the above

6. The term over potential is describe the

  1. The potential other than oxidation
  2. The potential other than reduction
  3. The potential used as calculated value
  4. The potential used higher than theoretical value

7. Karl Fischer volumetric titration is used for

A. To detect trace amount of organic solvent

B. To detect trace amount of water in organic solvent

C. To detect trace amount of solvent in water

D. To detect trace amount of sulfur in oil sample

8. Electrical double layer is refers to

A. The interface between a positively or negatively charged

B. Positive charge on the neutral molecule

C. Negative charge on the neutral molecule

D. Neutral molecule on the positive and negative charge

9. Voltammetric Electrochemical Cell

A. Current is measured in between reference and working electrode

B. Current is measured in between reference and axillary electrode

C. Current is measured in between working and axillary electrode

D. Current is measured on the reference electrode

10. In the electrochemical cell (Figure) magnetic stirring help to

Decrease the reaction time

  1. Increase the reaction time
  2. Increase the bubbles from sample solution
  3. Reduce the speed of ion transfer of analtyes to

the working electrode

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