Creating an Energy Efficient Engine
Trending Questions
Q. The above P-V diagram represents the thermodynamic cycle of an engine, operating with an ideal monoatomic gas. The amount of heat, extracted from the source in a single cycle is:
- PoVo
- (132)PoVo
- (112)PoVo
- 4PoVo
Q. If a fuel cell, methanol is used as fuel and oxygen gas is used as an oxidiser. The reaction is CH3OH(l)+32O2(g)→CO2(g)+2H2O(g)
At 298 K standard Gibb’s energies of formation for CH3OH(l), H2O(l), and CO2(g) are –166.2, –237.2 and −394.4 kJ mol−1, respectively. If the standard enthalpy of combustion of methanol is –726 kJ mol−1, the efficiency of the fuel cell will be:
At 298 K standard Gibb’s energies of formation for CH3OH(l), H2O(l), and CO2(g) are –166.2, –237.2 and −394.4 kJ mol−1, respectively. If the standard enthalpy of combustion of methanol is –726 kJ mol−1, the efficiency of the fuel cell will be:
- 80%
- 87%
- 90%
- 97%
Q. Heat is transferred to a heat engine from a furnace at a rate of 80 MW. If the rate of water heat rejection to a nearby river is 50 MW,
determine the thermal efficiency for this heat engine.
determine the thermal efficiency for this heat engine.- 47.5 %
- 27.5%
- 37.5%
- None of the mentioned
Q. Heat given to a system under isochoric process is equal to:
- W
- qp
- ΔU
- ΔH
Q. In a fuel cell, methanol is used as a fuel and O2 is used as an oxidizer. The standard enthalpy of combustion of methanol is −726 kJmol−1. The standard free energies of formation of CH3OH(l), CO2(g) and H2O(l) are − 166.3, −394.4 and −237.1 kJmol−1 respectively. The efficiency of the fuel cell will be:
- 66.2%
- 41.3%
- 85.1%
- 96.8%
Q. Heat is transferred to a heat engine from a furnace at a rate of 80 MW. If the rate of water heat rejection to a nearby river is 50 MW,
determine the thermal efficiency for this heat engine.
determine the thermal efficiency for this heat engine.- 47.5 %
- 27.5%
- 37.5%
- None of the mentioned
Q. (a) For the reaction
2AgCI(s)+H2(g)(1atm)⟶2Ag(s)+2H+(0.1M)+2CI−(0.1M),
ΔG∘ = - 43600 J at 25∘C.
Calculate the e.m.f. of the cell
[log 10−n=−n]
(b) Define fuel cell and write its two advantages.
2AgCI(s)+H2(g)(1atm)⟶2Ag(s)+2H+(0.1M)+2CI−(0.1M),
ΔG∘ = - 43600 J at 25∘C.
Calculate the e.m.f. of the cell
[log 10−n=−n]
(b) Define fuel cell and write its two advantages.
Q. Heat is transferred to a heat engine from a furnace at a rate of 80 MW. If the rate of water heat rejection to a nearby river is 50 MW,
determine the thermal efficiency for this heat engine.
determine the thermal efficiency for this heat engine.- 47.5 %
- 27.5%
- 37.5%
- None of the mentioned
Q. What will be the amount of heat evolved by burning 10 L of methane under standard conditions?
(Given heat of formation CH4, CO2 and H2O are −76.2, −398.8 and −241 kJmol−1 respectively)
(Given heat of formation CH4, CO2 and H2O are −76.2, −398.8 and −241 kJmol−1 respectively)
- 398.8 kJ
- 359.2 kJ
- 805.8 kJ
- 640.4 kJ
Q. Which one of the following is a state property?
- Heat
- Work
- Internal energy
- Potential energy
Q. Heat is transferred to a heat engine from a furnace at a rate of 80 MW. If the rate of water heat rejection to a nearby river is 50 MW,
determine the thermal efficiency for this heat engine.
determine the thermal efficiency for this heat engine.- 47.5 %
- 27.5%
- 37.5%
- None of the mentioned
Q. In a fuel cell (the device used for producing electricity directly from a chemical reaction) methanol is used as a fuel and oxygen gas is used as an oxidizer. The standard enthalpy of combustion of methanol is −726kJmol−1. The standard free energies of formation of CH3OH(l).CO2(g) and H2O(l) are −166.3, −394.4 and −237.1kJmol−1 respectively.
The standard free energy change of the reaction will be:
The standard free energy change of the reaction will be:
- −597.8kJmol−1
- −298.9kJmol−1
- −465.2kJmol−1
- −702.3kJmol−1
Q. In a fuel cell, methanol is used as a fuel and O2 is used as an oxidizer. The standard enthalpy of combustion of methanol is −726 kJmol−1. The standard free energies of formation of CH3OH(l), CO2(g) and H2O(l) are − 166.3, −394.4 and −237.1 kJmol−1 respectively. The efficiency of the fuel cell will be:
- 96.8%
- 66.2%
- 41.3%
- 85.1%
