How are you studying for Chem? (1 Viewer)

[Haku]

your welcome to apply... just write a damn good application.

do i write one to you? or someone else

 

[jm1234567890]

jm don't you want to do it?

nah, too busy these days.

modding forums takes some time.

do i write one to you? or someone else

yes, sending to me is fine.

 

[nwatts]

your welcome to apply... just write a damn good application.

Would nosadness increase his chances of gaining a modstick if he wrote his application in poetry form?

 

[bronze_nexus]

syllabus notes, past papers and studying off relevant class sheets.

 

[Casmira]

I'll get back on topic since you people cocked up the topic, here are my notes styrene/polystyrene

Styrene is the monomer used to create polystyrene, the systematic name for styrene monomer is ethenylbenzene, and polystyrene systematic name is polyethenylbenzene or polyphenylbenzene

Polystyrene comes in 2 distinct types, PS(Polystyrene) & PS Foam (styrofoam).

Polystyrene is a hard, clear, brittle plastic used in audiocassette/CD cases. PS Foam (known as expanded polystyrene with 95% air and 5% polystyrene), having the tradename of Styrofoam used by the general public,
Styrofoam is made by blowing hot gas through polystyrene liquid prior cooling & solidification, used in disposable drinking cups (foam cups), eskies, packing materials, & fast food containers due to its excellent ability as insulator, Styrofoam is also generally lightweight.

 

[Dreamerish*~]

Thanks Casmira.

There's another thing I'm confused about.

What is the the colour of the precipitate iron (II) hydroxide? That is, when hydroxide ions are added to a solution of iron (II).

Some textbooks say white turning quickly to brown, but others - and my tutoring notes - say grey-green. I asked Nit and Mitochondria and they both said grey-green. This morning I emailed my new tutor and he said it's white turning to brown.

Does anyone remember specifically what colour iron (II) hydroxide was during their precipitation prac? I remember vaguely that everything turned out the way I expected it to, and I've always known iron (II) hydroxide to be grey-green.

 

[MedNez]

What is the the colour of the precipitate iron (II) hydroxide? That is, when hydroxide ions are added to a solution of iron (II).

White to brown with NaOH, my notes say.

CC also agrees. Page 199 Table 6.1, "Tests used to identify cations".

 

[Casmira]

Thanks Casmira.

There's another thing I'm confused about.

What is the the colour of the precipitate iron (II) hydroxide? That is, when hydroxide ions are added to a solution of iron (II).

Some textbooks say white turning quickly to brown, but others - and my tutoring notes - say grey-green. I asked Nit and Mitochondria and they both said grey-green. This morning I emailed my new tutor and he said it's white turning to brown.

Does anyone remember specifically what colour iron (II) hydroxide was during their precipitation prac? I remember vaguely that everything turned out the way I expected it to, and I've always known iron (II) hydroxide to be grey-green.

i remember it went brown for me, maybe they had higher concetrations? lower concetrations?

 

[Haku]

i think for the white to brown its actually Iron(III)
not too sure on that...i think when u put that into NaOH solution it goes from white to brown.

anywayz, i am currently writing out an application form to jimo...hope i will pass!

Q: how does adding Chronium to steel (steel is iron with 1.5% carbon right?) make it more resistant to corrosion? also what does molybdemum do when added to steel?

 

[Dreamerish*~]

i think for the white to brown its actually Iron(III)
not too sure on that...i think when u put that into NaOH solution it goes from white to brown.

anywayz, i am currently writing out an application form to jimo...hope i will pass!

Q: how does adding Chronium to steel (steel is iron with 1.5% carbon right?) make it more resistant to corrosion? also what does molybdemum do when added to steel?

Is that shipwrecks?

 

[Haku]

Q: how does adding Chronium to steel (steel is iron with 1.5% carbon right?) make it more resistant to corrosion? also what does molybdemum do when added to steel?

to the iron thingy, i was right. the brown precipitate is iron(iii)(aq) + NaOH(aq) give Fe(OH)3, a brown precipitate. i think it only stay white for a second or so.

anywayz Fe(OH)2 is like dirty green or grey-green thats what u guys call it.

 

[Haku]

Is that shipwrecks?

yea its in shipwrecks.

so is steel like 1.5% carbon with iron?...and whats the thingy with like 0.1% and 0.8% carbon

about the cromium and molybdmum stuff help please

 

[Dreamerish*~]

anywayz Fe(OH)2 is like dirty green or grey-green thats what u guys call it.

I don't mean to sound like a prick, but did you, by any chance, get that from me?

I was very unsure about this, because my sources contradict each other, however, I asked my tutor and he said iron (II) hydroxide is creamy white, quickly turning to brown. I think I'm going to go with that.

If you got it from somewhere else, where? This thing is really annoying me.

 

[Haku]

I don't mean to sound like a prick, but did you, by any chance, get that from me?

I was very unsure about this, because my sources contradict each other, however, I asked my tutor and he said iron (II) hydroxide is creamy white, quickly turning to brown. I think I'm going to go with that.

If you got it from somewhere else, where? This thing is really annoying me.

wat u mean? i wrote that my self.

as the info state Iron(iii) the most commonly occuring iron ion is brown when mixed with NaOH, and iron(ii) is green. trust me. a friend is 2nd year uni does chemistry in advanced science and he looked it up too!

 

[Dreamerish*~]

wat u mean? i wrote that my self.

as the info state Iron(iii) the most commonly occuring iron ion is brown when mixed with NaOH, and iron(ii) is green. trust me. a friend is 2nd year uni does chemistry in advanced science and he looked it up too!

Yeah, I asked our Resident Chemist and Mitochondria (both of them know what they're talking about) and they told me that it's grey-green.

Then I asked my tutor, who has been a chemist his whole life, and he said it's creamy white turning to brown, which is what CC says.

In desperation, I called the HSC helpline, which gave me a third answer - green turning to brown.

I'm going to school next week and finding out for myself. '-_-

EDIT: Oh but this is really specific. I want to know because I'm just too curious, but if you're panicking over it - don't. The main thing is to identify that there is a precipitate.

 

[Haku]

Yeah, I asked our Resident Chemist and Mitochondria (both of them know what they're talking about) and they told me that it's grey-green.

Then I asked my tutor, who has been a chemist his whole life, and he said it's creamy white turning to brown, which is what CC says.

In desperation, I called the HSC helpline, which gave me a third answer - green turning to brown.

I'm going to school next week and finding out for myself. '-_-

EDIT: Oh but this is really specific. I want to know because I'm just too curious, but if you're panicking over it - don't. The main thing is to identify that there is a precipitate.

lol, ull prob get a 4th answer. i think u should stay with grey green for iron(ii)

anywayz can anyone answer my question on steel?

 

[Dreamerish*~]

lol, ull prob get a 4th answer. i think u should stay with grey green for iron(ii)

anywayz can anyone answer my question on steel?

http://community.boredofstudies.org/showthread.php?p=1907109#post1907109

Where it belongs.

 

[Haku]

lol, thanks for that.

thought that this forum is going everywhere with question might as well come out with another random...

 

[Captain Gh3y]

Molybdenum:

- Increases strength and hardness at high temp
- Increases resistance to corrosion
- Makes it easier to weld
- Makes it less brittle

Molybdenum steel is used in aircraft, vessles for use under high pressure and in car axles.

 

[Haku]

thanks, so basically Increases strength and hardness at high temp

and how does chronium help to resist corrosion when added to iron.

and is steel iron with 1.5% carbon?

and do we need to know those thing like wraught iron and stuff with diff amount of carbon in them?