Fuel Cells
Trending Questions
Q. In H2−O2 fuel cell the reaction occuring at cathode is:
- 2H2O+O2+4e−→4OH−
- 2H2+O2→2H2O(l)
- H++OH−→H2O
- H++e−→12H2
Q. The specific conductance of 0.1 N KCl solution at 23oC is 0.012 ohm−1cm−1. The resistane of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be:
- 0.142 cm−1
- 0.66 cm−1
- 0.198 cm−1
- 1.12 cm−1
Q.
Why are potassium and cesium, rather than lithium used in photoelectric cells?
Q.
Give the disadvantages of the dry cell?
Q.
Dry cell is source of which type of energy?
Q.
What is the reaction taking place in the fuel cell?
Q.
Write two advantages of a dry cell.
Q.
How many terminals are there in a dry cell?
Q. (a) Calculate ΔrG0 for the reaction
Mg(s)+Cu2+(aq)→Mg2+(aq)+Cu(s)
Given : E0cell=+2.71V, 1 F=96500Cmol−1
(b) Name the type of cell which was used in Apollo space programme for providing electrical power.
Mg(s)+Cu2+(aq)→Mg2+(aq)+Cu(s)
Given : E0cell=+2.71V, 1 F=96500Cmol−1
(b) Name the type of cell which was used in Apollo space programme for providing electrical power.
Q. During charging of lead storage battery:
PbO2 dissolves
- Lead sulphate gets deposited over the lead electrode
- Sulphuric acid is regenerated
- Concentration of H2SO4 decreases
Q. if for cell , deltaH of reaction is -285.8 kJ/mol.Enot of cell =1.23V.thermodynamic efficiency of fuel cell is (n=2)
Q. For the cell reaction at 25∘C,
Mg(s)+2Ag+(aq)⇌Mg2+(aq)+2Ag(s)
E0cell=+3.17 V
The values of Ecell, ΔG0 and Q respectively , at [Ag+]=10−3M and [Mg2+]=0.02 M are:
Here,
Q is reaction quotient
log 2=0.301
Mg(s)+2Ag+(aq)⇌Mg2+(aq)+2Ag(s)
E0cell=+3.17 V
The values of Ecell, ΔG0 and Q respectively , at [Ag+]=10−3M and [Mg2+]=0.02 M are:
Here,
Q is reaction quotient
log 2=0.301
- 3.04 V, −586.7 kJ mol−1, 2000
- 3.04 V, −611.8 kJ mol−1, 20000
- 3.13 V, −604 kJ mol−1, 20
- 3.30 V, −605.8 kJ mol−1, 2000
Q. Which of the following statement(s) regarding fuel cell is(are) true?
- They have efficiency of about 70%
- Its efficiency is less then conventional methods
- They do not cause pollution
- They use inexpensive fuels.
Q. One of the most successful fuel cell uses the reaction of hydrogen with oxygen to form water. The cell was used for providing electrical power in the Apollo space program. The water vapors produced during the reaction were condensed and added to the drinking water supply for the astronauts. In the cell, hydrogen and oxygen are bubbled through porous carbon electrodes into concentrated aqueous sodium hydroxide solution. Which of the following can be used as catalysts in order to increase the rate of electrode reactions in this fuel cell?
- Lithium
- Palladium
- Titanium
- All of above
Q. Which of the following statement(s) is/are correct for a dry cell battery?
- Carbon(graphite) rod will act as cathode
- Ammonia produced in the cell reaction will forms a complex with Zn2+
- Zinc metal will act as a anode
- Cell reaction will be reversed while passing current
Q.
Which cell has constant potential during its operation?
Fuel cell
Storage cell
Daniell cell
Mercury cell.
Q. The efficiency of a fuel cell is given by:
[1 Mark]
[1 Mark]
- ΔGΔS
- ΔGΔH
- ΔSΔG
- ΔHΔG
Q.
What is the efficiency of Fuel cell?
80-85%
70-75%
95%
90%
Q. Suggest two materials other than hydrogen that can be used as fuels in fuel cells.
Q.
Fuel which contains methane is-
Oil gas
Biogas
Liquified petroleum gas
Natural gas
Q. Choose the correct option(s) for the following concentration cell at 298 K:
Zn(s)|Zn2+(aq, C1)||Zn2+(aq, C2)|Zn(s)
C1 & C2 are concentrations of Zn2+ ions of each half-cell.
Zn(s)|Zn2+(aq, C1)||Zn2+(aq, C2)|Zn(s)
C1 & C2 are concentrations of Zn2+ ions of each half-cell.
- E0cell=0
- For a spontaneous reaction to take place, C1>C2
- For a spontaneous reaction to take place, C1<C2
- E0cell>0
Q. The efficiency of fuel cell is given by the expression, η is:
- η=−nFEcellΔH×100
- η=−nFEcellΔS×100
- η=−nFEcellΔA×100
- None of the above
Q. The electrode with reaction
Cr2O2−7(aq)+14H+(aq)+6e−→2Cr3+(aq)+7H2O(l)
can be represented as:
[If needed, use platinum as an inert electrode]
Cr2O2−7(aq)+14H+(aq)+6e−→2Cr3+(aq)+7H2O(l)
can be represented as:
[If needed, use platinum as an inert electrode]
- Pt(s)|H+(aq), Cr2O2−7(aq)
- H+(aq), Cr2O2−7(aq), Cr3+(aq)|Pt(s)
- Pt(s)|H+(aq)||Cr2O2−7(aq), Cr3+(aq)
- Pt(s), H2(g)|H+(aq), Cr2O2−7
Q. What are fuel cells? How are they different from Galvanic cells? Give the construction of hydrogen-oxygen fuel cells.
Q. The efficiency of a fuel cell is given by:
- ΔHΔG
- ΔGΔH
- ΔSΔG
- ΔGΔS
Q. Write the cathodic and anodic cell reactions of a Hydrogen-Oxygen fuel cell.
Q. Match the List-I with List-II:
List - I (Electrode) | List - II (Type) | ||
1. | Calomel | (A) | Reference |
2. | Glass | (B) | Redox |
3. | Hydrogen | (C) | Membrane |
4. | Quinhydrone | (D) | Gas |
- 1−B, 2−A, 3−D, 4−C
- 1−A, 2−C, 3−D, 4−B
- 1−C, 2−B, 3−A, 4−D
- 1−D, 2−A, 3−C, 4−B
Q. Which of the following statement regarding fuel cell is not true?
- Its efficiency is less then conventional methods
- They use inexpensive fuels.
- They do not cause pollution
- They have efficiency of about 70%
Q.
Theoretical efficiency of fuel cell is :
- 50%
- nearly 60%
- 33%
- nearly 100%
Q. Which of the following statement is not correct about an inert electrode in a cell?
- It does not participate in the cell reaction
- It provides surface for conduction of electrons
- It provides surface either for oxidation or for reduction reaction
- It provides surface for redox reaction