hey nice ppl need sum help (1 Viewer)

[joeylike2hiphop]

hey y`all i need some help!!!!. my skool is soon going to have a prac assesment based on acids and the environment and the production of materials. does ani1 out derehave ani ideas????fanz heaps

p.s. dreamish smells

 

[xiao1985]

go thru 3rd hand column and make sure u know how to design/write up a prac abt every single dp...

 

[mitochondria]

hey y`all i need some help!!!!. my skool is soon going to have a prac assesment based on acids and the environment and the production of materials. does ani1 out derehave ani ideas????fanz heaps

hey y'all I need some help!!!. my school is soon going to have a prac assessment based on The Acidic Environment and The Production of Materials. Does anyone out there have any ideas? Thanks heaps

I think that should help you a lot..

not to mention only the spelling mistakes have been corrected..

p.s. dreamish smells

we all smell.. but you smell worse than all of us combined ^______^

hope that helps

*sigh* yet another noob..

would another considering buying my new book, Evil Noob Army?

oops.. I've just thrown myself in merda profundissima.. when was the last time? It was munchkin right? hehehee.. she said I have something up my behind but I still haven't found anything

sorry just feeling mischievous right now..


p.s. get it right, it's Dreamerish not dreamish.. hence you smell more! touche! uhh.. QED!

 

[Dreamerish*~]

haha. you smell.

get your OWN burette this thursday.

 

[joeylike2hiphop]

hahahaha

aiya u micheavious basturd and u dreamish u gettin me a burette is like a dream come true so blah so fanz 2 de onli person to help me wit this p.s dreamish smells like ewwwww

 

[Jumbo Cactuar]

Maybe if you didn't try so hard to come across as an idiot we might respect your request to help you. If you can't even be bothered to make it easy for us, we are unlikely to help you out. Know that we are of no obligation.

 

[mitochondria]

umm.. what can I say?

I guess Jumbo Cactuar summed it up for me

but I must add that you're a.. bumhole joey that's a complement xD I think.. but it suits you one way or the other

*waves at the person who posted above me*

Finally get a chance to say hi to you without spamming too obviously.. but yes xD hello! Having need to carry two dozens of Krispy Kreme home is really embarrassing I wasn't sure whether people were drooling me or the Krispy Kreme I was carrying as a conclusion:

24 Kirspy Kreme Original Glazed = unwanted attention

anyways.. some chemistry for everyone

What happens when you heat a rubber band up? Does it expand or contract? And why?

Hint: get a rubber band, stretch it, feel it, and Le Chatelier's Principle

 

[Templar]

anyways.. some chemistry for everyone

What happens when you heat a rubber band up? Does it expand or contract? And why?

Hint: get a rubber band, stretch it, feel it, and Le Chatelier's Principle

Isn't it just that rubber is more entropically favourable to be in a shortened state, and the entropy overcomes enthalpy at higher temperatures?

I suppose you can say that as rubber stretch it's 'exothermic'.

 

[joeylike2hiphop]

ooohhhhhh

when u stretch a rubber band u feel it and its warmer correct? so if u use la chatelier principle contracted = expand plus energy due to the heat u feel of the rubber band. so if u add more heat then it would favour the contracted side so then it would contract if heat is added. im not sure since im not the smartest in chem( ai yah dreamerish beat me in chem ). please give answer this is a really interestin question.

 

[pseudobubble]

^^ interesting question! I guess I'd make this my first post. I think joey is right, I just tried it with a rubber band and it's warm when you stretch it, the "chemical equation" is probably something like:

rubber band -----> warm rubber band ∆H = -n (where n > 0)

So expansion of a rubber band is exothermic and contraction is endothermic therefore when you heat a rubber band up it'll probably contract!

I hope I get an answer =( mitochondria is probably lazy after flaming at someone

 

[mitochondria]

lol.. yes I was lazy

I'm not sure if you have met entropy before (it's not in the HSC syllabus but you *might* have come across it in your readings) but here it goes:

The "rubber molecules" (long chain polymeric hydrocarbons with smal branches) can order themselves differently at given temperatures. When the rubber band is stretched you can imagine the rubber molecules become "stretched", that is, more ordered and this process gives off heat. The underlaying principle is that if you supply heat to a system it will become more disordered - and if you apply this to a rubber band, microscopicly the molecules will try to arrange themselves to become as disordered as possible (i.e. all crunched up together, curling up in an odd fashion - what not) therefore when you heat a rubber band it will contract instead of expanding like common materials.

I hope that answered your question

 

[pseudobubble]

Yes, I have read about entropy =) My thoughts messed up and I confused myself after re-reading my last post. It all makes sense now, so thank you! ^^

By the way, that's a very cute avatar you have ^^

 

[kim_]

My school did one on production of materials based on the dot point "Define the molar heat of combustion of a compound and calculate the value for ethanol from first hand data." we had to find the enthalpy of propanol.

 

[miz2nv]

need help 4 chem we hve 2 make a model showing
hydrochloric acid and acetic acid any help with how they will look

please help

 

[hermand]

need help 4 chem we hve 2 make a model showing
hydrochloric acid and acetic acid any help with how they will look

please help

hydrochloric acid --> H-Cl
acetic acid --> H O
H-C-C-O-H
H
where the top h is bonded to the first carbon, the top O is double bonded to the second carbon, and the bottom h is bonded to the first carbon.

 

[miz2nv]

how would i make it in a model

 

[hermand]

use polystyrene balls, and make them like this, with a stick connecting the two 'molecules'.
hydrochloric acid http://upload.wikimedia.org/wikiped...el_2D.svg/558px-HCl_molecule_model_2D.svg.png
acetic acid [ball and stick model - best one.]
https://cornellbiochem.wikispaces.com/file/view/acetic.gif where the white is hydrogen, red is oxygen and grey is carbon, with two sticks between the c and the oxygen on its own.

 

[miz2nv]

thanks so much that was alot of help ,wif the hydrochloric acid fromwhat u shwon thts what i did but when i saw others there model was like they had 3 different balls reperestenting something any clue 2 y that

 

[hermand]

thanks so much that was alot of help ,wif the hydrochloric acid fromwhat u shwon thts what i did but when i saw others there model was like they had 3 different balls reperestenting something any clue 2 y that

they could have had h3o+ and cl- but that would be five. and way too complicated for [i'm guessing] year eleven chem.