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Question:

does anyone understand how a oxygen hydrogen fuel cell works?

If you do, then can you please help me with these questions? Ok so this is what I was given: An oxygen hydrogen fuel cell is widely used in a manned space vehicle. I was given a simplified diagram of the fuel cell ( sorry I can't show u). The hydrogen and oxygen gases are passed over platinum electrodes immersed in a solution of potassium hydroxide. when the cell is in operation water is produced. Assume that in the fuel cell, the oxygen gas reacts according to this equation: O2+4H+4e--2H2o1)Is the fuel cell galvanic or electrolytic?2) At which electrode (anode or cathode) does the oxygen half reaction occur? reason?3) write down an equation for the other half reaction that occurs.4) write down a balanced equation for the overall reaction in the fuel cell5) calculate the emf of the cell6) does the cathode experience a change in mass? reason?Please help! even if you answer one Q I'll be grateful!!!1)

Answer:

I think I understand this. It's true that you don't stick water in your car, you put in hydrogen. The hydrogen is made by electrocuting the water, which separates it into hydrogen and oxygen. The hydrogen, when it passes through the fuel cell recombines with oxygen, and this process releases energy basically. So the hydrogen is like a battery, the most efficient type of energy storage that we know if as I recall. Almost all of the energy used to make the hydrogen can be recouped from the fuel cell, thus why it's appealing technology. You can also combust it like gasoline, which is what's being done with the hydrogen 7 car by bmw. Basically gasoline or hydrogen have stored energy. You refine oil to make gasoline, which you can use in your car. You also basically refine hydrogen from water. It's also more appealing than gasoline because unlike gasoline we have lots of water, and the byproduct is water when it recombines with oxygen. So you use water to make it, and it emits water after it uses it, so in a way it's more cyclical than gasoline, which you burn and it turns into a gas from which you can no longer recoup energy.
1) galvanic, it makes electricity, it doesn't use it like an electrolytic cell would 2) cathode, positively charged cations move towards the cathode. The oxygen forms negative charges at the cathode that attracts the positive ions 3) 2?H+ + 2?e- ---H2 4) 4?H+ + O2(g) + 4?e? ---2H2O 5) emf +1.23V 6) No. The cathode isn't consumed in the reaction , it just offers a surface area for the gas to exchange ions on and carry the electricity away. Only the oxygen and hydrogen is consumed and the byproduct is water

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