Chemistry Test 2 2012

41 Questions | Total Attempts: 3031

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Chemistry Test 2 2012

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Questions and Answers
  • 1. 
    The electrolyte solution within the glass electrode (ref) of the pH meter is:
    • A. 

      Saturated KCl

    • B. 

      Concentrated HCl

    • C. 

      Dilute KC1

    • D. 

      Dilute HCl

    • E. 

      Dilute NaCl

  • 2. 
    The reaction that occurs in the electrolyte solution of the pCO2 electrode resulting in a change in pH is: 
    • A. 

      CO2 + H20 ----> H2CO3 ----> H+ + HCO3

    • B. 

      H+ + CO3- ----> H2CO3

    • C. 

      H2CO3 ----> H2O + CO2

    • D. 

      CO2 + H2O -----> 2H+ + CO3

  • 3. 
    Which of the following is NOT associated with a pCO2 electrode: 
    • A. 

      Membrane permeable to CO2

    • B. 

      PH electrode

    • C. 

      Measurement is amperometric

    • D. 

      Measurement is potentiometric

  • 4. 
    Electrodes made of pH sensitive glass may be used in the analysis of:
    • A. 

      PCO2

    • B. 

      PO2

    • C. 

      PH

    • D. 

      (a) and (c) are correct

    • E. 

      None of the above

  • 5. 
    The EMF of the sample cell is determined by which of the following formulas: 
    • A. 

      Ecell = Ecathode + Elj - Eanode

    • B. 

      Ecell = Eanode - Elj - Ecathode

    • C. 

      Ecell = Ecathode - Elj - Eanode

    • D. 

      Ecell = Eanode + Elj - Ecathode

  • 6. 
    In potentiometry, which of the following is considered the standard electrode?
    • A. 

      Calcium electrode

    • B. 

      Hydrogen electrode

    • C. 

      Potassium electrode

    • D. 

      Copper electrode

  • 7. 
    In an electrolytic cell, which of the following is the half-cell where reduction takes place?
    • A. 

      Anode

    • B. 

      Cathode

    • C. 

      Combination electrode

    • D. 

      Electrode response

  • 8. 
    Mercury covered by a layer of mercurous chloride in contact with saturated potassium chloride solution is a description of which of the following types of electrodes?
    • A. 

      Sodium

    • B. 

      Calcium

    • C. 

      Silver/silver chloride

    • D. 

      Calomel

  • 9. 
    Combination electrodes refers to which of the following?
    • A. 

      Reference and testing electrodes are assigned to different compartments closely linked

    • B. 

      Reduction takes place at the anode

    • C. 

      The testing electrode and reference are contained within a single unit

    • D. 

      The calomel electrode is a good example of a combination electrode

  • 10. 
    A pH/Blood gas analyzer contains a pH sensitive:
    • A. 

      Glass electrode which consists of silicon dioxide, sodium oxide, and aluminon oxide

    • B. 

      Electrode surface consisting of a polypropylene membrane permeable to H+

    • C. 

      Electrode surface consisting of a polypropylene membrane permeable to H2CO3/CO2

    • D. 

      Glass electrode which is permeable to H+

  • 11. 
    Monitoring the current at an electrolytic electrochemical cell that is generated at a fixed voltage and is proportional to the concentration of analyte present in the test sample in solution is referred to as:
    • A. 

      Coulometry

    • B. 

      Potentiometry

    • C. 

      Osmometry

    • D. 

      Amperometry

  • 12. 
    Incorporation of ____, into a polyvinyl chloride membrane allows for the manufacture of an ion-selective electrode that is highly selective for calcium. 
    • A. 

      Di-p-octylphenyl phosphate

    • B. 

      Nonactin

    • C. 

      Valinomycin

    • D. 

      Erythromycin

  • 13. 
    Which one of the following is used both as an internal reference element in potentiometric ion-specific electrodes and as an external reference electrode half-cell of constant potential required to complete a potentiometric cell?
    • A. 

      Calomel

    • B. 

      Mercury vapour

    • C. 

      Silver/silver chloride

    • D. 

      Platinum

  • 14. 
    Which of the following conditions are among the requirements for a Nernst equilibrium potential to exist for a given charged ion species across a semipermeable membrane, as in an ion-selective electrode?
    • A. 

      The semipermeable membrane must be permeable to many ion species

    • B. 

      A concentration gradient for a given charged ion species must exist across that membrane.

    • C. 

      If a membrane is permeable to two different ion species, then the ion activity of both species can be measured.

    • D. 

      The membrane potential across a semipermeable membrane must be constantly changing.

  • 15. 
    The reference potential of a silver-silver chloride electrode is determined by the: 
    • A. 

      Concentration of potassium chloride filling solution

    • B. 

      Surface area of the electrode

    • C. 

      Activity of total anion in the paste covering electrode

    • D. 

      Concentration of silver in the paste covering electrode

  • 16. 
    Ion-selective analyzers using undiluted samples have what advantage over analyzers that use diluted sample?
    • A. 

      They can measure over a wider range of concentration

    • B. 

      They are not subject to pseudohyponatremia caused by high lipids or high proteins

    • C. 

      They do not require temperature equilibration

    • D. 

      They require less maintenance

  • 17. 
    The ability of an indicator (measuring) electrode to respond to a single species of ion and not any other is referred to as:
    • A. 

      Sensitivity

    • B. 

      Accuracy

    • C. 

      Precision

    • D. 

      Selectivity

  • 18. 
    Of the following half cell reactions, identify the oxidation reactions: 
    • A. 

      Zn ---> Zn 2+ + 2e-

    • B. 

      Cu2+ + 2 e- ----> Cu

    • C. 

      2H + 2 e- ----> H2

    • D. 

      Al ----> Al3+ + 3e-

    • E. 

      Only a and d

    • F. 

      Only b and c

  • 19. 
    What is the correct order of migration towards the anode of the following proteins in serum protein electrophoresis: fibrinogen, albumin, IgD, transferrin, haptoglobin?
    • A. 

      Fibrinogen, IgD, Haptoglobin, Transferrin, Albumin

    • B. 

      Fibrinogen, IgD, Transferrin, Haptoglobin, Albumin

    • C. 

      IgD, Fibrinogen, Transferrin, Haptoglobin, Albumin

  • 20. 
    Immunofixation electrophoresis
    • A. 

      Combines the techniques of zone electrophoresis, isotachophoresis, isoelectric focusing, and gel electrophoresis in small-bore fused silica capillary tubes.

    • B. 

      Involves exposure of electrophoresed proteins to antisera against different immunoglobulin heavy and light chains with resultant precipitation.

    • C. 

      Involves transfer of separated proteins to a strip of nitrocellulose by electroblotting followed by an immunochemical reaction with a specific antibody.

    • D. 

      Uses electrophoresis in two dimensions to assess global changes in protein expresssion.

  • 21. 
    On a serum protein electrophoresis, if the albumin band appears distorted and large, the likely cause is: 
    • A. 

      PH of electrophoretic buffer incorrect

    • B. 

      Instrument not connected

    • C. 

      Sample overload

    • D. 

      Inappropriate support material used

  • 22. 
    If an electrophoretic buffer were diluted before use instead of using it at normal strength, how would electrophoresis be affected?
    • A. 

      Increased migration rate of protein

    • B. 

      Decreased migration rate of protein

    • C. 

      No change in the rate of migration of protein

  • 23. 
    Upon receiving a serum sample for protein electrophoresis, which you perform using agarose gel. You note that the specimen is hemolyzed. How would hemolysis affect the banding pattern of this type of electrophoresis?
    • A. 

      There would be an increased alpha1-globulin band

    • B. 

      There would be a decreased beta-globulin band

    • C. 

      There would be an increase in the gamma globulin bands

    • D. 

      A decreased alpha2-globulin band

  • 24. 
    How does the new charge of the proteins in a sample affect the electrophoretic mobility of protein fractions?
    • A. 

      It is inversely proportional to electrophoretic mobility

    • B. 

      It is directly proportional to electrophoretic mobility

    • C. 

      It is equal to the electrophoretic mobility

    • D. 

      There is no relationship between net charge and electrophoretic mobility

  • 25. 
    What would the concentration of albumin be if the total protein value was 85 g/dL and the densitometer measured the albumin fraction to be 55% of the total, what is the albumin concentration?
    • A. 

      Albumin values cannot be calculated using densitometry

    • B. 

      15.4 g/dL

    • C. 

      0.65 g/dL

    • D. 

      46.8 g/dL

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