Option 2 - Shipwrecks, Corrosion and Conservations (1 Viewer)

[tomato_sauce217]

haha... i don't like ship wrecks much.. i had really NO interest in it.. but in my trials i stuffed that sectoion lost like 14 marks ... and only got 75 % in my trials so i swore i was gonna study hard for shipwrecks...

now i come to fink about it.. it's pretty much work it... because iknow how to do all da question except the faraday one i BS it... and went on to talk about the voltage and stuff.. i donno they should pick up the right answer in there some where..

HEy for the LAST question
i said the ship on the shore would corrode faster... because it's exposed to 20% of oxygen in the atmosphere comparing to 1% oxygen in the water... and it's got higher temperature as well... i donno... some one said the COMpletely opposite

 

[tina_goes_doo]

I was thinking the ship on shore would corrode faster, then studied the picture and saw it was true. I would like to know why the window was broken in the picture. Vandals? Or something more sinister like the corrosion of glass

 

[VVoody]

I was thinking the ship on shore would corrode faster, then studied the picture and saw it was true. I would like to know why the window was broken in the picture. Vandals? Or something more sinister like the corrosion of glass

The window was made of steel....

 

[Atotoi]

aha im sure it was woody....
Maybe the ship was boarded by pirates and they took the people on board hostage, breaking the windows too...placing them on their own boat.. then letting the ship to beach itself on shore - where it corroded.
However when another ship came along that night , the pirates were nearby and sank it with Cannons... Damn you Johnny Depp!!

Hmm i wonder if keira knightley can make a cameo in this story??



PS - i think the two exams in the one day has sent me cuckoo

 

[mathock]

haha i think this question would have been easier if the pic wasnt there, i was looking at it thinking... the one on the beach looks more corroded, theyre trying to trick me arent they?? hang on?? i was so confused so i disregarded the picture completely... and got the right answer haha great test board of studies, you pricks

 

[VVoody]

aha im sure it was woody....
Maybe the ship was boarded by pirates and they took the people on board hostage, breaking the windows too...placing them on their own boat.. then letting the ship to beach itself on shore - where it corroded.
However when another ship came along that night , the pirates were nearby and sank it with Cannons... Damn you Johnny Depp!!

Hmm i wonder if keira knightley can make a cameo in this story??



PS - i think the two exams in the one day has sent me cuckoo

Clearly it was the killer coconuts. The ship that sunk was trying to get away but was filled with coconuts so sank. The other one wasn't so lucky and there was many a feast for the few days after that...

Yep...killer coconuts that eat steel....yep

 

[Enigmatic Eve]

For the level of corrosion for the 2 ships, I explained that the ship on the shore/beach would corrode faster because the higher oxygen levels and temperature, which favour the acceleration of corrosion. But then, doesn't sea water also favour acceleration of corrosion since it is an electrolyte, and allows movement of free ions? So in that question, I was pretty much confused.
Good luck to everyone with the rest of the their exams!!

 

[lozza_86]

didnt mind this one too much. thought it was a bit easy, so you would have had to pack so much info in to get your marks worth which is a bit of a bugger but like has been said before if you knew your stuff and your syllabus, you were set

 

[VVoody]

For the level of corrosion for the 2 ships, I explained that the ship on the shore/beach would corrode faster because the higher oxygen levels and temperature, which favour the acceleration of corrosion. But then, doesn't sea water also favour acceleration of corrosion since it is an electrolyte, and allows movement of free ions? So in that question, I was pretty much confused.
Good luck to everyone with the rest of the their exams!!

Yea the high humidy and temp = fast corrosion

I said that at 30m down it was cold enough to slow dow corrosion substancially. How cold is it at the deph anyway?

 

[lucyinthehole]

haha i think this question would have been easier if the pic wasnt there, i was looking at it thinking... the one on the beach looks more corroded, theyre trying to trick me arent they?? hang on?? i was so confused so i disregarded the picture completely... and got the right answer haha great test board of studies, you pricks

what do you mean? the one on the beach WAS more corroded

 

[Jezzabelle]

yes water forms an electrolyte BUT the question didnt ask you that, it specifically said temperature and heat. So the one on the beach is more corroded AND it wasnt a trick question, you were supposed to be accounting for observations, hence the drawing supports your answer.

Highest oxygen layer occurs on the surface of water due to photosynthesis of plankton, the deeper the water gets the less oxygen concentration due to the respiration of marine organism 'using up' the oxygen. In the deepest ocean however oxygen level rises again because of cool highly oxygenated current flow from the polar seas. At 30m it is assumed that the oxygen concentration is low, its not deep enough to be getting a current from polar seas. Since corrosion is dependant on oxygen and water (due to the test you had to describe in previous answer..) and less oxygen=less rate corrosion. The ship underwater had a slower corrosion rate to the ship above on sand. The ship on the sand was subject to oxygen in the air, and also water spray (from surface that is high oxygen concentration) and white wash/waves up onto the sand (also surface sea water high oxygen concentration). Thus one concludes that the ship on land was exposed to a higher concentration and corroded more readily then the one underwater.

All reactions procede faster at a higher temperature (even redox ones) due to the particle theory (yr11 prelim) that on heating the molecules vibrate more readily=more collisions=reaction procedes faster. As the ship on land was exposed to direct radiated heat from the sun, it was in a higher temperature environment to the ship underwater.... (some physics blah here but ultimetly it has to do with refraction/reflection index of light waves from a less dense to greater dense material) where the light waves dont penetrate to 30 metres ( i assume anyways i dont go scuba diving), so the water is colder (and also you got those cold polar currents underneath 30 metres... blah blah heat rises..trust me the water is cold). So wat does this conclude. Well that the ship on land was in a reaction environment of higher temperature to the ship underwater and thus more energy to particles=they faster faster=more collisions (yeh i am repeating myself) = faster move rate.

the ship on land had the conditions of higher temperature and oxygen concentration to favour a higher corrosion rate then the one under water with relatively less oxygen and lower temperature. This accounts for the observed greater corrosion of the ship on land.
OK !! and thats what i wrote in the test and i swear i am 100% correct

 

[lucyinthehole]

sounds good to me. mostly cos i said something like that too, and i like being reassured

 

[thaoroxy2001]

I asked my teacher after exam and he laughed he said that it was kinda a trick question.... it was important to state the effect of temp and oxygen concentration on the ships and how it would effect corrosion...but most people will tend to stop there and rely on diagram...off course people are saying why would they draw that picture?...well the question didn't specifically say...LOOK AT THE CORROSION ON THE BOATS...the picture was there to show the locations of the boats...he said that best answer would be to explain effects but then also introducing the saltwater electrolyte in the response...so in theory the boat on land would corrode more if we were only looking at oxygen conc and temp but we must remember that the presence of salt water increases the rate of corrosion ...boat on land may get corrosion during high tide but boat in water would be more corroded due to the higher potential for salt water to act as electrolyte...remember in class prac with the different corrosion rate of iron nails in different environments...the salt water even at low temps corroded the most.

and another thing...30m under water is not very deep...oxygen concentrations are greatest in water above 100m due to photosynthesis of aquatic plants.

 

[DeMikez]

haha i think this question would have been easier if the pic wasnt there, i was looking at it thinking... the one on the beach looks more corroded, theyre trying to trick me arent they?? hang on?? i was so confused so i disregarded the picture completely... and got the right answer haha great test board of studies, you pricks

the one on the shore is more corroded.. it has a higher surrounding temperature.. it has more oxygen to react with.. and the water is sprayed onto the ship hence more surface area for the oxyen to react with the water acting as an electrolyte..
the ship underwater (although only 30m down) has (apparently) less oxygen to react with and its surrounding temperature is cooler than the ship up above.. the oygen also has lesser of a surface area to react with the water since the water is surrounded by water instead of oxygen (if u get what i mean)

newayz thats what i put down.. hopefully i can get some marks..

gud lukz wid ur tha subjects peeps..

 

[Bej]

Grimreaper aka gareth is a nerd

See that gareth, thats you

On the subject of the test, it was easy, i mean common. Even though alot of the questions were stupid rope learning ones which i really dont like, i belive the whole school system has gone down hill, where its not about understanding its about memorising stuff, which is why i hardly do any study and still beat everyone in the class (except gareth but hes a nerd and looks like the guy in the picture). Ill prob get 80+ raw on that test, ant to know my secret? I ENJOY MY SUBJECTS therefore learn more than rope learning people (girls)
in conclusion girls are icky

 

[vicksta]

The word is roTe learning, not roPe learning!!!

 

[alien]

i talked about how the submerged ship had less oxygen and a lower temperature so that preserved it somewhat. but the other one was exposed to the air, and was constantly damp so had ideal conditions for corrosion (the hot sand was warm, salt water as an electrolyte etc. etc.)