shipwrecks, corrosion n conservation (3 Viewers)

[Dumsum]

Think about what would happen if the nail was removed. Exactly the same thing to the magnesium dissolving and iron ions coming out of solution. .'. the magnesium has no influence on the nail, the nail has no influence on anything, and could thus potentially rust etc

 

[thunderdax]

I'm not talking about the anode, I'm talking about the nail. How could the solution be the cathode? definition of an electrode is: A conducting terminal of a cell. The solution could never be an electrode.

 

[AreYouAlright?]

I'm not talking about the anode, I'm talking about the nail. How could the solution be the cathode? definition of an electrode is: A conducting terminal of a cell. The solution could never be an electrode.

I suggest very candidly that you go back to the VERY FIRST module you studied in HSC Chemistry and look at your syllabus and read up about Metal displacement reactions, you can then come back and i'll happily discuss this further.

 

[Dumsum]

Displacement reactions nothing to do with anodes and cathodes.

 

[gogogadgetbrain]

I'm not talking about the anode, I'm talking about the nail. How could the solution be the cathode? definition of an electrode is: A conducting terminal of a cell. The solution could never be an electrode.

dude. look up the definition of an electrode and realise there are non in this particular reaction

 

[Abtari]

yea, as stated earlier in my post, it would probably be wrong to say that iron deposits on the iron nail, rather it would do so at the 'bottom of the beaker' due to sheer force of newton's gravity, nothing else...

u would lose a mark at max for saying that...i.e. one chemical principle not demonstrated/or not shown by the student as knowing it blablabla...

but the rest as dumsum, areualrite, thunderdax et al have said is quite right in my opinion.

 

[missjelly_baby]

um if they wanted to ask a question on metal displacement reactions wouldn't they have asked it in the main body of the paper? The question was specifically for shipwrecks therefore questions would have to come from only the shipwrecks dot points.

 

[Haku]

don;t base it on that. use some common sense and look at the diagram and think. would i be wrong to say that the iron would actually form on the magnesium?

 

[Captain Karl]

We learnt that even though the reaction occurs in the same vessel it can still be an electron transfer reaction. My teacher was pretty awesome - she knew what she was talking about. Unless i had some kinda misunderstanding I'm almost certain it was a redox reaction. It would be hard to call it a certified galvanic cell because there's no external wire, but i'm sure its a redox reaction

 

[Dumsum]

We learnt that even though the reaction occurs in the same vessel it can still be an electron transfer reaction. My teacher was pretty awesome - she knew what she was talking about. Unless i had some kinda misunderstanding I'm almost certain it was a redox reaction. It would be hard to call it a certified galvanic cell because there's no external wire, but i'm sure its a redox reaction

Of course it's a redox reaction--Magnesium atoms are being oxidised and Iron ions are being reduced. Point is the iron nail has nothing to do with that.

 

[Captain Karl]

I'm sure that the iron doesnt form on the magnesium. I'm also sure that you can come up with an argument to say that it will. I still believe that the iron will form on the nail and not on the magnesium or the bottom of the beaker

 

[Dumsum]

I'm sure that the iron doesnt form on the magnesium. I'm also sure that you can come up with an argument to say that it will. I still believe that the iron will form on the nail and not on the magnesium or the bottom of the beaker

What would happen if you removed the nail? So say if you just put magnesium in a solution of iron sulfate.

 

[Captain Karl]

Point taken, but then its got nothing to do with the option topic. Still, the iron would form on the bottom of the beaker in that case and not on the magnesium strip

 

[Haku]

i don;t see why no though. it wouldn't make anything wrong.

 

[gogogadgetbrain]

What would happen if you removed the nail? So say if you just put magnesium in a solution of iron sulfate.

this thread and the other one (which is pretty much the same) are going in circles...i pretty much said the exact same thing in the other thread a couple of hours ago.

in summary if you're going to go against people like dumsum and myself you need to understand that electrons cannot float around in an electrolyte and therefore the iron ions will come out of solution on the magnesiums surface - as the magnesium is oxidised the iron that was attached to it will have nothing to 'hold' on to and will fall to the botttom of the beaker

i put down that the lead may undergo rusting- an independant process to the magnesium/iron ions redox reaction

 

[Haku]

this thread and the other one (which is pretty much the same) are going in circles...i pretty much said the exact same thing in the other thread a couple of hours ago.

in summary if you're going to go against people like dumsum and myself you need to understand that electrons cannot float around in an electrolyte and therefore the iron ions will come out of solution on the magnesiums surface - as the magnesium is oxidised the iron that was attached to it will have nothing to 'hold' on to and will fall to the botttom of the beaker

i put down that the lead may undergo rusting- an independant process to the magnesium/iron ions redox reaction

lol, so initially iron would basically form on the mg surface

 

[Captain Karl]

To tell you the truth i'm starting to swing around to your way of thinking. The way I answered the question but i said that if you connected the two metals to a voltmeter you would get a reading, making it a proper cell. The I answered it made sense in the exam but then again so do a lot of answers that turn out to be wrong...

 

[Haku]

would it record a voltage?

i don't think so.

 

[AreYouAlright?]

would it record a voltage?

i don't think so.

I'm quite certain it would! If it was connected via external wire it would become a galvanic cell definitely!

I'd just like to point out that I have always had the same argument... NOT galvanic, formed on bottom of beaker! Nothing happens to Iron nail...

Debate what you will but the chemistry of it is quite clear.

 

[Captain Karl]

If you connected the two metals to a voltmeter they would record a voltage (electrons would flow through the voltmeter from the magnesium to the iron, just not 100% of them). I'm not certain about the other parts but that i'm 100% on