Chemistry Discussion - My god is Thorium - General

[QUOTE=joe588;39550195]thanks still don't get it though. where does ka = 1.8x10^4 come in? is it just simply [H+] = 0.0046?[/QUOTE] Ka is the acid dissociation constant. It's a unique constant for each acid, and is a measure of the equilibrium between the acid and the ions it forms. In this case it's the equilibrium constant of: HCOOH <--> H+ + HCOO- It can also be given as pKa which is the log10 of the Ka as there is such a huge range of possible Ka values. You need the Ka value to work out the [H+] in this case.

[img]http://i.imgur.com/lNIb4n8.png[/img] there's your final expression: Ka does come in. just treat the whole thing like algebra, because that's exactly what it is [editline]11th February 2013[/editline] hth

does [H+] = 9.09x10^4 then? i'm shit at algebra :( (4.6x10-3 mol dm−3 solution. Ka = 1.8x10^4 ) meaning the pH is 3.04?

Does anyone know what the strongest water based electrolyte solution you can make at home would be?

[QUOTE=joe588;39550752]does [H+] = 9.09x10^4 then? i'm shit at algebra :( (4.6x10-3 mol dm−3 solution. Ka = 1.8x10^4 ) meaning the pH is 3.04?[/QUOTE] I think you missed the - off the [H] and Ka exponents, since 1.8x10^4 and 9.09x10^4 are gigantic numbers for this calculation :v: but assuming those are just mistakes in typing it up for this forum, and you meant 9.09x10^-4, yeah those answers are both right, good job. what kind of work are you doing? so far, this just seems to be A-level chemistry, and I'm just remembering what I can. also, algebra is extremely useful for just about anything science-related so I suggest brushing up on it if you're not so hot on it at the moment

yeah man missed the -, thanks! you lot fucking own. doing a natural science degree with the open university. currently chemistry basics, it goes from GCSE level to a-level/first year uni in a book. starts off with the usual then the last third is mostly organic chemistry. i left the book at work though and in an entire day of reading stuff on the internet you guys explained it better, so thanks a lot i appreciate it! (i also assumed after reading the first few chapters it'd just be gcse level stuff so didn't bother looking at the rest until a few days ago, whoops)

nice, a natsci degree is totally a good investment for the future

[QUOTE=ultra_bright;39550836]Does anyone know what the strongest water based electrolyte solution you can make at home would be?[/QUOTE] Simple NaCl is pretty strong. There might be strong bases or acids in some household products, but I wouldn't recommend messing with them...

Lab write-ups are always fun.

[QUOTE=elitehakor v2;39555262]Lab write-ups are always fun.[/QUOTE] Indeed. Sample A reacts with sample B to produce a white precipitate, blah blah blah.

For all you experimental chemists, [URL="http://www.amazon.com/Images-SI-Inc-Uranium-Ore/dp/B000796XXM/ref=sr_1_1?ie=UTF8&qid=1360645638&sr=8-1&keywords=uranium+238"]http://www.amazon.com/Images-SI-Inc-Uranium-Ore/dp/B000796XXM/ref=sr_1_1?ie=UTF8&qid=1360645638&sr=8-1&keywords=uranium+238[/URL] enjoy some uranium

Make UF6 for no reason? I do enjoy the comments for that product though.

[QUOTE=ultra_bright;39550836]Does anyone know what the strongest water based electrolyte solution you can make at home would be?[/QUOTE] What do you mean by strongest?

[QUOTE=Turnips5;39550421][img]http://i.imgur.com/lNIb4n8.png[/img] there's your final expression: Ka does come in. just treat the whole thing like algebra, because that's exactly what it is [editline]11th February 2013[/editline] hth[/QUOTE] If you don't mind me asking, why does [H+] = [HCOO-] ?

[QUOTE=Pedophila;39562049]If you don't mind me asking, why does [H+] = [HCOO-] ?[/QUOTE] [IMG]http://f2.braxupload.se/hodk8i.3930b0916f.png[/IMG] [editline]12th February 2013[/editline] For every HCOOH, there will be a HCOO- and a H+

6 posts later and stuck again. how the fuck would these two molecules bind on the -NH2 group? i've had 3 attempts are any right or even close to right? no idea what i'm doing here so any pages that you know of that could explain it would be awesome too ---- or would it bind to the benzene ring instead of the carboxylic group

I think you would form what is called a Peptide bond. The NH2 and the OH would react to give H20 as a by product, and a bond through the N with a H attached. It's like your second example, but take the single bonded O off, and a H from the N. So you would have: ¦-CH2-CH2-NH-C(O)-¦ Sorry if that's hard to understand, not got a decent drawing tool on this computer. Look up peptide bonds if you need some examples :) Edit: Also, as extra information, a compound with a C(O)NH peptide bond is called an Amide

Are those possible/probable answers? Because it looks like a condensation reaction with -NH- + H20. [editline]12th February 2013[/editline] Use this, its a freeware molecular drawing program.[QUOTE=Cakebatyr;39542010]I just found out [url=http://www.acdlabs.com/resources/freeware/chemsketch/]Chemsketch[/url] has a freeware version! Aww yeah! [img]http://i.imgur.com/a55eneP.png[/img] [editline]10th February 2013[/editline] I'm abusing bond angles! (I didn't hit F9 to normalize bonds) [img]http://i.imgur.com/en8roZQ.png[/img] [editline]10th February 2013[/editline] Diethanal, 1,2-cyclopropandione, tetramethanol, propan-1,3-al-2-one, bicyclo[2,2,0]pentane, 1,2-cyclopropandione, acetic acid (methyl acetate), and a carboxylic functional group.[/QUOTE]

[QUOTE=Yellowamoeba;39563696]I think you would form what is called a Peptide bond. The NH2 and the OH would react to give H20 as a by product, and a bond through the N with a H attached. It's like your second example, but take the single bonded O off, and a H from the N. So you would have: ¦-CH2-CH2-NH-C(O)-¦ Sorry if that's hard to understand, not got a decent drawing tool on this computer. Look up peptide bonds if you need some examples :) Edit: Also, as extra information, a compound with a C(O)NH peptide bond is called an Amide[/QUOTE] Thanks dude, that's billiant! will look up now ^ yeah downloaded that, will give it a go. they're not the possible answers, they're just what i randomly bodged together. this look better then? [img]http://i.imgur.com/bCFxgKY.png[/img] [editline]12th February 2013[/editline] i think i've understood this correctly?? [img]http://i.imgur.com/iadBY1I.png[/img]

Yup both of those are correct now!

[QUOTE=elitehakor v2;39555262]Lab write-ups are always fun.[/QUOTE] yeahhhh. this is my last one [img]http://www.mikeh269.com/filedump/report.png[/img]

is it essential to use such tiny fonts in lab writeups? all papers seem to be written like that, it's not good for a blindy like me

Analytical chem midterm in 2 hours, 20 minutes. Lets see how well I understand statistics. [Sp]Not at all[/sp]

I've got an electrochemistry exam tomorrow. Hopefully I'll get an A on it

My kinetics test was incredibly easy. Two AP Questions with almost no math involved.

[QUOTE=joe588;39564323]Thanks dude, that's billiant! will look up now ^ yeah downloaded that, will give it a go. they're not the possible answers, they're just what i randomly bodged together. this look better then? [IMG]http://i.imgur.com/bCFxgKY.png[/IMG] [/QUOTE] Actually, I think what happens here is that the carboxylic acid will protonate the amine group to give an amine-carboxylate salt (that is, R-NH[SUB]3[/SUB][SUP]+ [/SUP]and R-COO[SUP]-[/SUP]). This prevents condensation from happening as the amine group is no longer nucleophilic and thus cannot attack the electrophile (which, in this case, will be the carboxylic acid group).

[QUOTE=elitehakor v2;39578899]I've got an electrochemistry exam tomorrow. Hopefully I'll get an A on it[/QUOTE] Instead of studying for my exam I spent all night playing Mount and Blade Warband i r smart

[QUOTE=Cakebatyr;39558849]Make UF6 for no reason? I do enjoy the comments for that product though.[/QUOTE] "Great Product, Poor Packaging May 14, 2009 By Patrick J. McGovern I purchased this product 4.47 Billion Years ago and when I opened it today, it was half empty." Hahaha

[media]http://www.youtube.com/watch?v=-FWGDtfwn3A[/media] I'v wanted to do this with a five pound gummy. They got the title wrong, it's potassium chlorate. Also, I like the part where they try to put out the chemical fire by suffocating it.

So in my last year of highschool during chem we had to make esters for one prac. At the end of the class every group had to go around to every other group and smell their esters and attribute a smell to it (after smelling and identifying their own ester). So after we had all finished and had let our teacher know we all had to get to it. The prac manual (and the teacher) had both specified to hold our heads somewhat above the beaker and to waft the fumes up to our noses, NOT to put our faces right over the beakers and take a deep breath. Somehow I managed to miss BOTH of these instructions and did the exact thing I wasn't supposed to! Our ester's odour? Banana! The next groups ester? Banana! The one after that? Banana! The one after that? Banana! ... for about a week I could smell NOTHING but fucking (fake) banana. Fuck esters!