Engineering Chemistry Multiple Choice Questions on “Fuel Cells”.
1. A fuel cell is used to convert chemical energy into ____________
a) Mechanical energy
b) Solar energy
c) Electrical energy
d) Potential energy
Answer: c
Clarification: A fuel cell is used to convert chemical energy into electrical energy through a chemical reaction of positively charged hydrogen ions with oxygen or another oxidizing agent.
2. Select the incorrect statement from the following option.
a) Fuel cells have high efficiency
b) The emission levels of fuel cells are far below the permissible limits
c) Fuel cells are modular
d) The noise levels of fuel cells are high
Answer: d
Clarification: The noise levels of fuel cells are low. They have high efficiency and are modular but the emission levels of fuel cells are far below the permissible limits.
3. ______________ and suitable catalyst are required to promote high rate of electrode processes.
a) Lower temperature
b) Higher temperature
c) Moderate temperature
d) Very low temperature
Answer: b
Clarification: Higher temperature and suitable catalyst are required to promote the high rate of electrode processes. The reaction at the anode produces electricity and water as by-products. The catalyst lowers the activation energy required, allowing the reaction to proceed more quickly or at a lower temperature.
4. Fuel cells are free from vibrations, heat transfer and thermal pollution.
a) True
b) False
Answer: a
Clarification: Fuel cells are free from vibrations, heat transfer and thermal pollution. The first commercial use of fuel cells came more than a century later in NASA space programs to generate power for satellites and space capsules.
5. A stable interface between solid _________ liquid ____________ and gaseous ___________ promotes high rate of electrode processes.
a) Fuel, electrolyte, electrode
b) Electrode, fuel, electrolyte
c) Electrode, electrolyte, fuel
d) Fuel, electrode, electrolyte
Answer: c
Clarification: A stable interface between solid electrode, liquid electrolyte and gaseous fuel promotes high rate of electrode processes. Electrodes are always solid and electrolyte is always in liquid phase.
6. Which of the following is not an example of a fuel cell?
a) Hydrogen-oxygen cell
b) Methyl-oxygen-alcohol cell
c) Propane-oxygen cell
d) Hexanone-oxygen cell
Answer: d
Clarification: Hydrogen-oxygen cell, methyl-oxygen-alcohol cell and propane-oxygen cell are some of the examples of fuel cells. Hexanone-oxygen cell is not an example of a fuel cell.
7. The electrolytic solution used in a hydrogen-oxygen fuel cell is ____________
a) 75% KOH solution
b) 25% KOH solution
c) 75% NaOH solution
d) 25% NaOH solution
Answer: b
Clarification: The electrolytic solution used in a hydrogen-oxygen fuel cell is 25% KOH solution by volume.
8. The standard emf of the hydrogen-oxygen fuel cell is ____________
a) 1.23 V
b) 2.54 V
c) 3.96 V
d) 0.58 V
Answer: a
Clarification: The standard emf of the hydrogen-oxygen fuel cell is 1.23 V. This type of cell operates efficiently in the temperature range 343 K to 413 K.
9. The residual product discharged by the hydrogen-oxygen cell is ____________
a) Hydrogen peroxide
b) Alcohol
c) Water
d) Potassium permanganate
Answer: c
Clarification: The residual product discharged by the hydrogen-oxygen cell is water. It is formed by the oxidation reaction taking place at electrodes and combining the hydrogen and oxygen molecules.
10. Hydrogen-oxygen fuel cell can produce drinking water of potable quality.
a) True
b) False
Answer: a
Clarification: Hydrogen-oxygen fuel cell can produce drinking water of potable quality because the residual product discharged by the hydrogen-oxygen cell is water which is in its pure form.