Ion Analysers Ion Analysers Multiple Choice Questions And Answers

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Ion Analysers Multiple Choice Questions And Answers

1. The dilution of solution must not reduce the level of ammonia below _________
a) 10-2 M
b) 10-5 M
c) 10-8 M
d) 10-9 M
Answer: 10-5 M.

2. When electrode potential response is plotted as a function of ammonia concentration on a semi-log graph, the graph obtained will be ____________
a) A straight line
b) Parabolic
c) Sigmoidal
d) A curve
Answer: A straight line.

3. If a solid or liquid membrane is placed in pure water, the membrane dissolves slightly, producing an equilibrium concentration of the measured ion. This is represented as __________
a) A constant, Eo
b) Activity
c) Blank correction, Cb
d) Concentration of standard solution, Cs
Answer: Blank correction, Cb.

4. In liquid membrane electrode, the liquid ion exchanger is held in a porous disc of _____________
a) Solid material
b) Semi-permeable membrane
c) Hydrophobic material
d) Water absorbing material
Answer: Hydrophobic material.

5. Ion selective electrodes have ________ linear range and _________ detection limit than the pH electrode.
a) Lower, lower
b) Lower, higher
c) Higher, lower
d) Higher, higher
Answer: Lower, higher.

6. In recent liquid membrane electrodes, the porous liquid membrane is replaced with which of the following?
a) Polyvinyl chloride
b) Polyacryl chloride
c) Polyester membrane
d) Polyacryl amide
Answer: Polyvinyl chloride.

7. Which of the following specifies the relation between ionic strength and activity coefficient?
a) Directly proportional
b) Inversely proportional
c) Equal
d) No particular relation
Answer: Inversely proportional.

8. Which of the following is used in potassium electrode in liquid membrane electrodes?
a) Ionomycin
b) Valinomycin
c) Nonactin
d) Gramicidin
Answer: Valinomycin.

9. Which of the following is not the characteristic of ion selective electrodes?
a) It is fragile
b) Easy to use
c) Available in different sizes and shapes
d) It is insensitive to many ions
Answer: It is fragile.

10. Which of the following is the effective concentration measured at the electrode head?
a) Selectivity coefficient
b) Ionic strength
c) Activity
d) Activity coefficient
Answer: Activity.

11. In solid state membranes, the body of the electrodes are made of which of the following?
a) Polyvinyl chloride
b) Plastic
c) Polythene
d) Teflon
Answer: Teflon.

12. In glass membrane electrode, the glass containing 11% Na2O, 18% Al2O3, 71% SiO2 is highly sensitive to which of the following ions?
a) Sodium
b) Hydrogen
c) Nitrogen
d) Chlorine
Answer: Sodium.

13. Which of the following is not a problem of ion selective electrodes?
a) Interference with other ions
b) Output is influences by ionic strength
c) Drift in electrode potential during a sequence of measurements
d) Can measure only positive ions
Answer: Can measure only positive ions.

14. The value of activity coefficient is always in which of the following ranges?
a) Zero
b) Less than zero
c) Less than 1
d) Greater than 1
Answer: Less than 1.

15. Which of the following is not the characteristic of ion selective electrodes?
a) Simple to use
b) Inexpensive
c) Narrow concentration range
d) Operates in wide range of temperature
Answer: Narrow concentration range.

16. Which of the following is the only operator entry required in PC-based ion analysers?
a) Hardware set-up
b) Signal measurement
c) Calibration
d) Sample calculation
Answer: Calibration.

17. During which of the following conditions is the blank correction not necessary?
a) If sample concentration rises in linear response region
b) If sample concentration falls in linear response region
c) If sample concentration rises in non-linear response region
d) If sample concentration falls in non-linear response region
Answer: If sample concentration falls in linear response region.

18. In carbon dioxide electrode, the membrane separates which of the following?
a) Sodium carbonate, magnesium chloride
b) Magnesium hydrogen carbonate, sodium chloride
c) Sodium hydrogen carbonate, sodium chloride
d) Magnesium carbonate, magnesium chloride
Answer: Magnesium hydrogen carbonate, sodium chloride.

19. Which of the following gas permeable membrane is used for carbon dioxide gas sensing electrode?
a) Silicon rubber
b) PVC membrane
c) Fluorocarbon
d) Polythene
Answer: Silicon rubber.

20. Ion analysers need calibration once in which of the following durations?
a) Every two or three hours
b) Every nine or ten hours
c) Every 24 hours
d) Every 48 hours
Answer: Every two or three hours.

21. The presence of dirt or moisture degrades which of the following?
a) Circuit components
b) High input impedance of buffer amplifier
c) Low input impedance of buffer amplifier
d) Low output impedance of buffer amplifier
Answer: High input impedance of buffer amplifier.

22. In ion analysers, which of the following serve the dual purpose of controlling the operating current of FET and providing current gain?
a) FET itself does it
b) SCR
c) Op-amp
d) Diode
Answer: Op-amp.

23. Which of the following is not a type of ground in ion analyser?
a) Chassis and electrostatic ground
b) Digital ground
c) Analog ground
d) Reference ground
Answer: Reference ground.

24. During which of the following conditions is the blank correction necessary?
a) If sample concentration rises in linear response region
b) If sample concentration falls in linear response region
c) If sample concentration rises in non-linear response region
d) If sample concentration falls in non-linear response region
Answer: If sample concentration falls in non-linear response region.

25. Biosensors measure glucose concentrations between which of the following ranges?
a) 10^-1 to 10^-2 M
b) 10^-2 to 10^-4 M
c) 10^-1 to 10^-4 M
d) 10^-1 to 10^-7 M
Answer: 10^-1 to 10^-7 M.

26. For constructing the glucose sensor, which of the following is used as a gel?
a) Urea
b) Urease
c) Acrylamide
d) Polyacrylamide
Answer: Polyacrylamide.

27. Which of the following is the physico-chemical component?
a) Enzymes
b) Anti-bodies
c) Transducer
d) Cells or tissues
Answer: Transducer.

28. Which of these biosensors use the principle of heat released or absorbed by a reaction?
a) Potentiometric biosensor
b) Optical biosensors
c) Piezo-electric biosensors
d) Calorimetric biosensors
Answer: Calorimetric biosensors.

29. An example of biosensor, urea electrode makes use of which of the following electrodes?
a) Carbon dioxide electrode
b) Ammonia electrode
c) Fluoride electrode
d) Ammonium electrode
Answer: Ammonium electrode.

30. Which of the following is not a characteristic of the immobilized enzymes?
a) They cannot be re-used
b) It produces reproducible results
c) Stability exists
d) Same catalytic activity is present for number of analysis
Answer: They cannot be re-used.

31. In glucose electrode, glucose oxidase has been coupled to an electrode by which of the following materials?
a) Ferrocene derivatives
b) Urease
c) Polyacrylamide
d) Biochips
Answer: Ferrocene derivatives.

32. The biocatalytic membrane is attached to the glass electrode using which of the following materials?
a) Nylon mesh
b) Teflon
c) Silicon rubber
d) Polythene
Answer: Nylon mesh.

33. Which of the following materials are used as a gel to which biocatalytic membrane is fixed in ammonia selective electrode?
a) Urea
b) Urease
c) Acrylamide
d) Polyacrylamide
Answer: Acrylamide.

34. Transducers employed in the bulk of enzyme electrodes use which of the following principles?
a) Amperometric
b) Optical
c) Magnetic
d) Colorimetric
Answer: Amperometric.

35. Which of the following biosensors use the movement of electrons produced during redox reactions?
a) Amperometric biosensor
b) Potentiometric biosensors
c) Piezo-electric biosensors
d) Optical biosensors
Answer: Amperometric biosensor.

36. The biocatalytic membrane used in the ammonia selective electrode is which of the following?
a) Urea
b) Urease
c) Acrylamide
d) Polyacrylamide
Answer: Urease.

37. Biocatalytic membrane electrode cannot be used for the measurement of which of the following gases?
a) Ammonia
b) Carbon dioxide
c) Hydrogen
d) Nitrogen
Answer: Nitrogen.

38. Which of the following reference electrode is placed in the solution of carbon dioxide electrode?
a) Calomel electrode
b) Silver/silver chloride electrode
c) Mercury/mercury sulphate electrode
d) Glass electrode
Answer: Silver/silver chloride electrode.

39. Which of the following gas permeable membrane is used for ammonia gas sensing electrode?
a) Silicon rubber
b) Microporous Teflon membrane
c) Fluorocarbon
d) Polythene
Answer: Fluorocarbon.

40. How can samples above 1M in ammonia concentration be measured using ammonia electrode?
a) It must be diluted and measured
b) It cannot be measured
c) The electrode has to be modified for measuring
d) It can be measured directly
Answer: It must be diluted and measured.

41. Which of the following causes main interference in Fluoride electrode?
a) H+ ions
b) OH– ions
c) Li+ ions
d) Cl– ions
Answer: OH– ions.

42. Which of the following factors does not the reproducibility of the ammonia electrode?
a) Temperature
b) Drift
c) Noise
d) Dilution
Answer: Dilution.

43. Crystal membrane of ion selective electrode can be regenerated by washing with which of the following?
a) Alcohol
b) Iodine solution
c) Acidic solution
d) Basic solution
Answer: Alcohol.

44. In fluoride ion electrode, the potential corresponding to level of the fluoride ion is described by which of the following equations when E is the measured electrode potential, Eo is the reference potential and A is the level of fluoride ions in solution?
a) E=Eo+0.0591 log A
b) E=Eo-0.0591 log A
c) E=Eo+0.0896 log A
d) E=Eo-0.0896 log A
Answer: E=Eo-0.0591 log A.

45. In Ammonia electrode, diffusion of dissolved ammonia occurs through the membrane until which of the following conditions occur?
a) Concentration becomes equal on both sides
b) Activity becomes equal on both sides
c) Partial pressure becomes equal on both sides
d) Differential pressure is low
Answer: Partial pressure becomes equal on both sides.

46. What does TISAB which is used to overcome interferences stand for?
a) Total Isolation Strength Absolute Buffer
b) Total Ionic Strength Absolute Buffer
c) Total Ionic Strength Adjustment Buffer
d) Total Isolation Strength Adjustment Buffer
Answer: Total Ionic Strength Adjustment Buffer.

47. For fluoride electrode, the electrode response curve will not only shift but will change slope with changes in temperature.
a) True
b) False
Answer: True

48. The performance of ammonia electrode is not affected by sample colour and turbidity.
a) True
b) False
Answer: True.

49. The response time of the biocatalytic electrode is a function of the thickness of the enzyme layer.
a) True
b) False
Answer: True.

50. The response time of the biocatalytic membrane electrode is poor when used with complex organic molecules.
a) True
b) False
Answer: False.

50. Ion selective electrode are unaffected by colour or turbidity of the solution.
a) True
b) False
Answer: True.

51. The timing for a microprocessor and for all signals is generated by the CPU clock.
a) True
b) False
Answer: True.

52. The analog and digital grounds are connected together in ion analysers.
a) True
b) False
Answer: False

53. Nanoscopic optical biosensors have fast response time but the sensitivity is reduced.
a) True
b) False
Answer: False.

54. In glucose sensor, a measure of change in oxygen value is a measure of the glucose value.
a) True
b) False
Answer: True.

55. The difference between measured activity and actual concentration becomes higher at higher concentration. Is this statement true or false?
a) True
b) False
Answer: True.


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