Shipwrecks (1 Viewer)

[mitchwong650]

Uhh dude..

Then the aluminium around the iron nail corrodes and the nail falls of neway ROFL

u had to say that they should use other means of attaching the guttering like plastic shit, glue, intert crap i dunno i wrote stuff tho. (read this in CSSA paper answer or NEAP asnswer can't remember)

i did say aluminum is better tho.

i touched on that too, just in case, however the question specifically asked about the GUTTER only, not the steel nails... but oh well.

 

[NoName91]

i touched on that too, just in case, however the question specifically asked about the GUTTER only, not the steel nails... but oh well.

I mentioned that copper guttering would be useful in that the iron in the steel would oxidise in preference HOWEVER the properties and additives within the steel would prevent it from corrosion. I didn't really know to be honest.

 

[sam5]

for the second part of the first section in shipwrecks, i expalined the effectiveness of methods such as galvanisation, surface alloys and use of passivating metals. Was that sufficient?

 

[NoName91]

for the second part of the first section in shipwrecks, i expalined the effectiveness of methods such as galvanisation, surface alloys and use of passivating metals. Was that sufficient?

Sounds good. I noted that all contained potential electrolyte solutions, hence the need to protect. Can = Aluminium, disposable, thin, susceptible to corrosion upon scratching etc. Tin = Stainless steel becuase designed for use over a longer period of time, alloyed with nickel etc. for strength. Tuna tin...... um.....no idea haha

 

[sam5]

thats good. thanks mate.

 

[Mc Fadge]

I found it hard to answer the first question not know what the container holding the sardines was made out of, or is this something that everyone just kindof knows?

 

[sam5]

I found it hard to answer the first question not know what the container holding the sardines was made out of, or is this something that everyone just kindof knows?

yeah its a general thing that were meant to know - aluminium.

 

[walk]

Tin plated steel cans are still used to hold food (as well as polymer coated cans) - so couldn't the questions have also wanted you to talk about the relatively low activity of tin so it doesn't react with most food - but the problem of the tin surface being broken to expose the steel underneath - this would accelerate the corrosion of the steel - this is why you should not buy dinted cans?

 

[mahdi]

Yer...

Platinum (anode) - not silver as it is in a SCHOOL laboratory
Artifact (cathode)
Silver nitrate - electrolyte

Platinum is more expensive than silver you egg. . .

 

[mahdi]

Aliminum coz its passivating and has a higher oxn potential that iron , steel as in the question so it will prefertially corrode becoming anode,whilst iron steel wteva u wanna call it is reduced since corrosion is a oxn reduction reactionn

I loved this section !!!!!!!!!

You had to say copper should be used for the guttering. Because the steel screws will transfer electrons to the copper, so the copper would corrode slowly (screws act as sacrificial anodes).

If aluminium was used then the guttering would transfer electrons to the screws, making it corrode fast (guttering acts as a sacrificial anode). The passivating thing is correct, but in a real life situation they would use copper for the guttering.

 

[Michaelmoo]

You had to say copper should be used for the guttering. Because the steel screws will transfer electrons to the copper, so the copper would corrode slowly (screws act as sacrificial anodes).

If aluminium was used then the guttering would transfer electrons to the screws, making it corrode fast (guttering acts as a sacrificial anode). The passivating thing is correct.

I started off by explaining "the chemistry involved" as it said. Talking about oxidation potentials etc. If you look at it in terms of relative activity, yes copper will be favourable as it will act as the cathode, and the screws will act as anodic sites. Since the screws are easier/cheaper to replace, it would make sense to choose copper.

Although, in the end, I mentioned Aluminium's ability to passivate and concluded that this property means it will in fact be the most favourable.

but in a real life situation they would use copper for the guttering

Lol as for this, I don't think so. Aluminium is in fact predominanetly used for guttering (along with galvanised iron). Lots of reasons: Corrosion resistance, relatively light, durable etc.

 

[slamduncs]

I started off by explaining "the chemistry involved" as it said. Talking about oxidation potentials etc. If you look at it in terms of relative activity, yes copper will be favourable as it will act as the cathode, and the screws will act as anodic sites. Since the screws are easier/cheaper to replace, it would make sense to choose copper.

Although, in the end, I mentioned Aluminium's ability to passivate and concluded that this property means it will in fact be the most favourable.



Lol as for this, I don't think so. Aluminium is in fact predominanetly used for guttering (along with galvanised iron). Lots of reasons: Corrosion resistance, relatively light, durable etc.

It's passivating nature doesn't prevent corrosion when it is in contact with a less reactive metal.

 

[Michaelmoo]

It's passivating nature doesn't prevent corrosion when it is in contact with a less reactive metal.

Um yer it does. It's passivating nature protects itself (not the less reactive metal). But it will preferentially oxidise anyway, because it is the more active metal.

In effect, by choosing aluminium, there will be no corrosion.

 

[slamduncs]

Um yer it does. It's passivating nature protects itself (not the less reactive metal). But it will preferentially oxidise anyway, because it is the more active metal.

In effect, by choosing aluminium, there will be no corrosion.

Hope you didn't write that.

 

[Michaelmoo]

Hope you didn't write that.

Meh, I'm no good at chem neway.

 

[Live Laugh Love]

I fucked this section up sooo bad.