What is the standard EMF of hydrogen oxygen fuel cell?
What is the standard EMF of hydrogen oxygen fuel cell?
1.23 V
Explanation: 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.
What is the overall reaction in the hydrogen oxygen fuel cell?
2H2(g)+O2(g)→2H2O(l)
How do you write half equations for fuel cells?
Starts here2:56Half Equations and Fuel Cells | 9-1 GCSE ChemistryYouTubeStart of suggested clipEnd of suggested clip52 second suggested clipAnd these electrons that are lost from hydrogen therefore instead present at the electrode. GivingMoreAnd these electrons that are lost from hydrogen therefore instead present at the electrode. Giving it its negative charge. We can write a half equation for what’s happening at the anode.
What is the oxidation half reaction for a fuel cell?
Half-reactions that release electrons are called oxidation reactions; half-reac- tions that accept electrons are called reduction reactions. Inside a PEM hydrogen fuel cell, electric current is generated using the two chemi- cal half-reactions shown below. The electrode where oxidation occurs is called the anode.
What is the standard EMF of the given fuel cell?
The theoretical electromotive force (emf) E of a hydrogen-oxygen fuel cell is the difference of these two electrode potentials, written as follows. where E° is the standard electromotive force for this cell, and is expressed as E° = E°O2 – E°H2; at 25 °C (298K) and atmospheric pressure, it is equal to 1.23 V.
What is EMF value of fuel cell?
The ideal voltage of steady-flow fuel cells is usually expressed by Emf = −ΔG°/nF where ΔG° is the “Gibbs free energy of reaction” for the oxidation of the fuel at the supposed temperature of operation of the cell. Furthermore, the ideal power of the cell is expressed as the product of the fuel flow rate with this emf.
What is the standard potential for the cell reaction in the hydrogen oxygen fuel cell used in space vehicles?
Molecular oxygen is reduced at the cathode and combined with protons to form water. The theoretical voltage for a hydrogen fuel cell should be 1.23 V, however typical potentials are 0.6 to 0.7 and actually drop as the current flows.
What is the balanced equation for the overall reaction in a hydrogen fuel cell?
When hydrogen reacts with oxygen by burning, the chemical energy is given out as heat. A fuel cell converts chemical energy directly into electrical energy – there is no heat. The overall reaction is: 2H 2 + O 2 → 2H 2O with electrons being exchanged from the cathode to the anode.
What is the word equation for the reaction in a hydrogen fuel cell?
What is the standard cell potential for this fuel cell?
Although the standard potential of the reaction is 1.23 V, because of kinetic overpotentials each fuel cell in the power train operates at a voltage of about 0.70 V. Despite this energy loss, the fuel cell system is still about twice as efficient as a combustion engine performing the same reaction.
Why do you need oxygen in a hydrogen fuel cell?
Hydrogen is the basic fuel, but fuel cells also require oxygen. One great appeal of fuel cells is that they generate electricity with very little pollution–much of the hydrogen and oxygen used in generating electricity ultimately combine to form a harmless byproduct, namely water.
