Special Designs of Ion Selective Electrodes Questions & Answers
1. 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: c
Explanation: Gas permeable membrane used for ammonia sensing electrode is fluorocarbon membrane. For each gas different membranes are used.
2. 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: a
Explanation: Gas permeable membrane used for carbon dioxide sensing electrode is silicon rubber membrane. For each gas different membranes are used.
3. The response time of biocatalytic membrane electrode is poor when used with complex organic molecules.
a) True
b) False
Answer: b
Explanation: The response time of biocatalytic membrane electrode is good even when used with complex organic molecules. But, the membrane is costly.
4. 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: b
Explanation: A silver/silver chloride reference electrode is placed in the solution. A glass electrode is also placed in the solution but it is not a reference electrode.
5. 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: d
Explanation: Biocatalytic membranes cannot be used for the measurement of nitrogen. It can be used for the measurement of other three gases.
6. The biocatalytic membrane used in ammonia selective electrode is which of the following?
a) Urea
b) Urease
c) Acrylamide
d) Polyacrylamide
Answer: b
Explanation: The biocatalytic membrane used in ammonia selective electrode is urease. It is used for the detection of ammonia.
7. Which of the following materials are used as gel to which biocatalytic membrane is fixed in ammonia selective electrode?
a) Urea
b) Urease
c) Acrylamide
d) Polyacrylamide
Answer: c
Explanation: The material used as gel to which biocatalytic membrane is fixed in ammonia selective electrode is acrylamide. This is attached to the ion selective electrode directly.
8. 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: a
Explanation: The biocatalytic membrane is attached to the glass electrode using nylon mesh. Cellophane film can also be used.
9. The response time of the biocatalytic electrode is a function of thickness of the enzyme layer.
a) True
b) False
Answer: a
Explanation: The response time of the biocatalytic electrode is a function of thickness of the enzyme layer. It is also a function of diffusion of the layer in the sample solution.
10. 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: b
Explanation: In carbon dioxide electrode, the membrane separates sodium hydrogen carbonate and sodium chloride. Sodium hydrogen carbonate is the internal electrolyte.