Chemistry has me by the balls guys.
I love science, but my Chem course this year (final year high school course) is a rollercoaster of fuck off.
I was doing alright at first, then we got introduced to acids and bases and my dick went flaccid. Got a test back: 51%, worst mark I ever got on any test in my entire life. Everyone else did awesome. This was also the first time I legitimately did not understand something, other times in other subjects I was just being a lazy fuck. But I had no fucking clue how to do that shit.
Midterms approached, I refused to do any work because I'm an idiot and the best way to understand things is to totally not do the work while accepting defeat, and everyone is all, "Oh, dude, you're going to fail so fucking bad," and "Man you might need to do another year of school if do this in all courses, y'know that right?" to which I agreed.
But then, the eve of the Chem Midterm arrived, leaving me with 6 hours to play League of Legends and 2 hours to watch Khan Academy videos on the Acids/Bases playlist.
Got my midterm mark back on Monday, I got a 90%, a fucking NINETY PERCENT, whilst everyone else who ~PAID ATTENTION~ and memorized the fuck out of the formulas we're given got from 33% to 71%. I'm pretty sure I got the second highest mark out of 140 students.
The moral of the story is: learn your own way, and by understanding rather than repetition. (The two are not always related.) Also, Sal Khan is a legend and will probably help me do good throughout my education career. Anyone who isn't already aware of Khan Academy, go check it out, it will help you on nearly any subject, and his videos are in-depth in the good way.
That was actually my experience with high school chem, only course I failed three consecutive tests, then the next two I got 90+%.
First year university chemistry, which is essentially in-depth high school chemistry was much easier and clearer.
[QUOTE=Cakebatyr;39521890]That was actually my experience with high school chem, only course I failed three consecutive tests, then the next two I got 90+%.
First year university chemistry, which is essentially in-depth high school chemistry was much easier and clearer.[/QUOTE]
I hope that's the case. The course I'm doing is taught as a mixture of paradoxical exceptions to make things easier to understand, and that we don't need to know certain things because "scientists already proved it." If university Chem is like that, I'm dropping my science-y end-goal and becoming a carpenter.
So we synthesized acetylsalicylic acid (aspirin) in class and one of the byproducts is acetic acid (and the catalyst we used was phosphoric acid). During the lab I felt the scent of acetic acid and it brought back memories of my chemistry set I used to have as a kid and I thoughtlessly placed my nose over the beaker and did a powerful sniff.
tl;dr it burned
I just had my finals for my AP Chem exam. Went into the exam with a 100%. Left with a 100%.
[QUOTE=Zerohe;39521820]Chemistry has me by the balls guys.
I love science, but my Chem course this year (final year high school course) is a rollercoaster of fuck off.
I was doing alright at first, then we got introduced to acids and bases and my dick went flaccid. Got a test back: 51%, worst mark I ever got on any test in my entire life. Everyone else did awesome. This was also the first time I legitimately did not understand something, other times in other subjects I was just being a lazy fuck. But I had no fucking clue how to do that shit.
Midterms approached, I refused to do any work because I'm an idiot and the best way to understand things is to totally not do the work while accepting defeat, and everyone is all, "Oh, dude, you're going to fail so fucking bad," and "Man you might need to do another year of school if do this in all courses, y'know that right?" to which I agreed.
But then, the eve of the Chem Midterm arrived, leaving me with 6 hours to play League of Legends and 2 hours to watch Khan Academy videos on the Acids/Bases playlist.
Got my midterm mark back on Monday, I got a 90%, a fucking NINETY PERCENT, whilst everyone else who ~PAID ATTENTION~ and memorized the fuck out of the formulas we're given got from 33% to 71%. I'm pretty sure I got the second highest mark out of 140 students.
The moral of the story is: learn your own way, and by understanding rather than repetition. (The two are not always related.) Also, Sal Khan is a legend and will probably help me do good throughout my education career. Anyone who isn't already aware of Khan Academy, go check it out, it will help you on nearly any subject, and his videos are in-depth in the good way.[/QUOTE]
I know that feel man. I barely got a B last semester
[img_thumb]http://i.imgur.com/jmXk9b5.png?1[/img_thumb]
My grades go all over the place. On my last test I got a 62% and have to do test corrections over the weekend, any additional credit to be given at the mercy of my teacher who has little faith in us anyway since about 1/3 of my class doesn't do homework (its not graded) so they bomb all the tests and hes sick of giving make-up test points.
I will say he is probably the best teacher I've had in regards to grading on a high-level student level. Only Tests, Labs, and Quizzes are graded.
[QUOTE=RIPBILLYMAYS;39523563]I know that feel man. I barely got a B last semester
[img_thumb]http://i.imgur.com/jmXk9b5.png?1[/img_thumb]
My grades go all over the place. On my last test I got a 62% and have to do test corrections over the weekend, any additional credit to be given at the mercy of my teacher who has little faith in us anyway since about 1/3 of my class doesn't do homework (its not graded) so they bomb all the tests and hes sick of giving make-up test points.
I will say he is probably the best teacher I've had in regards to grading on a high-level student level. Only Tests, Labs, and Quizzes are graded.[/QUOTE]
i took college chem last semester. failed every exam except for the first, got a 50% on the final and around the same on 3 of the 4 other exams.
still got a b in the class because of how much fucking effort i put into it. did all the extra credit, had perfect attendance, averaged 98% in the labs.
[QUOTE=JohanGS;39522715]So we synthesized acetylsalicylic acid (aspirin) in class and one of the byproducts is acetic acid (and the catalyst we used was phosphoric acid). During the lab I felt the scent of acetic acid and it brought back memories of my chemistry set I used to have as a kid and I thoughtlessly placed my nose over the beaker and did a powerful sniff.
tl;dr it burned[/QUOTE]
Did you not learn anything from safety orientations?!
gotta waft nigga
[QUOTE=Cakebatyr;39523782]Did you not learn anything from safety orientations?![/QUOTE]
I don't think the smelling part was brought up, at least I didn't remember it at the time (I think the teacher assumed we learnt it from earlier classes, but I used to be quite indifferent in school, despite good grades). I've grown since then though.
[editline]9th February 2013[/editline]
[QUOTE=TehWhale;39523854]gotta waft nigga[/QUOTE]
Yeah, the teacher said that after I exclaimed the Swedish equivalent of cunt.
[QUOTE=Cakebatyr;39523782]Did you not learn anything from safety orientations?![/QUOTE]
Mannequins burn near fire. From our ACS safety video.
[QUOTE=Boomslang;39517069]We were using it in a titration to determine the concentration of Fe(II) and Fe(III) in a mixed solution. I believe the Mercuric Chloride was used to react with excess tin in the solution. I had no idea about the reactions with aluminium, lucky there wasn't any nearby![/QUOTE]
It doesn't blow up, aluminum metal treated with mercuric chloride forms an amalgam perfect for reducing p2np to amphetamine.
I'm currently in Honors Chemistry in High School and we just started Stoich.
Fuck.
[QUOTE=kaine123;39525990]I'm currently in Honors Chemistry in High School and we just started Stoich.
Fuck.[/QUOTE]
That's one of the easier topics I thought.
Studying to be a laborantti (not sure what it is in English specifically, but basically lab assistant).
Got bored one lesson a while back, had little to do, so did that one QI hydrogen experiment.
[video=youtube;NkS2AJavwSo]http://www.youtube.com/watch?v=NkS2AJavwSo[/video]
Didn't work as well as this one, turns out the generic dishwashing liquid we had doesn't do bubbles very well :/
[QUOTE=kaine123;39525990]I'm currently in Honors Chemistry in High School and we just started Stoich.
Fuck.[/QUOTE]
make sure you learn your dimensional analysis
[QUOTE=kaine123;39525990]I'm currently in Honors Chemistry in High School and we just started Stoich.
Fuck.[/QUOTE]
How many grams of zinc is in 0.542g of zinc acetate (Zn(CH3COO)2)?
[QUOTE=Cakebatyr;39529666]How many grams of zinc is in 0.542g of zinc acetate (Zn(CH3COO)2)?[/QUOTE]
bout three fiddy
[editline]9th February 2013[/editline]
Don't mean to steal the question, but I want to jog my memory.
[SP]You get the molar mass of zinc acetate and then divide the molar mass of zinc by the total Mm, correct? That gives you 35.6% percent composition, I think.
So 0.542 * 0.356 = 0.193 grams?[/SP]
[QUOTE=Sgt Doom;39526279]Studying to be a laborantti (not sure what it is in English specifically, but basically lab assistant).
Got bored one lesson a while back, had little to do, so did that one QI hydrogen experiment.
[video=youtube;NkS2AJavwSo]http://www.youtube.com/watch?v=NkS2AJavwSo[/video]
Didn't work as well as this one, turns out the generic dishwashing liquid we had doesn't do bubbles very well :/[/QUOTE]
My Higher chem teacher did it with methane. The methane burn is way more impressive.
How can I extract acetic acid from vinegar? I was thinking of boiling it but the boiling points are very close
100C for water and 118C for Acetic acid
should I try extractive distillation
[QUOTE=Elfy;39533113]How can I extract acetic acid from vinegar? I was thinking of boiling it but the boiling points are very close
100C for water and 118C for Acetic acid
should I try extractive distillation[/QUOTE]
Don't bother distilling it, doesn't work.
You could evaporate it slowly and you'll get the acetic acid powder out...
Yay for kinetics test on Tuesday. Our high school merged AP Chem and Chem II, so I'm getting both for 90 minutes every day.
balancing reactions with two of the same element on either side of the plus sign always grabs me by the balls and twists
something like this: Fe2O3 + CO --> Fe + CO2
gets me every single fucking time and i hate it
[QUOTE=Angus725;39533731]Don't bother distilling it, doesn't work.
You could evaporate it slowly and you'll get the acetic acid powder out...[/QUOTE]
Pretty sure acetic acid is a liquid
[QUOTE=download;39536718]Pretty sure acetic acid is a liquid[/QUOTE]
It's not. It's just dissolved in water. The H+ ions cause the acidity, and you only have H+ ions when you dissolve it.
[editline]10th February 2013[/editline]
Also, it's always fun to to put hydrogen chloride and sodium hydroxide together.
If you have exactly the right amount of each, it doesn't create a deadly acid or base, but it creates salty water.
[QUOTE=download;39536718]Pretty sure acetic acid is a liquid[/QUOTE]
Google acetic acid powder.
Heh, acid-base chem. There's a bit more to it than H and OH.
i can't get my head around chirality
[img]http://i.imgur.com/UNQjSs2.png[/img]
i thought it was top right and the middle but are they achiral? or neither . wtf.
[QUOTE=Boaraes;39536572]balancing reactions with two of the same element on either side of the plus sign always grabs me by the balls and twists
something like this: Fe2O3 + CO --> Fe + CO2
gets me every single fucking time and i hate it[/QUOTE]
The answer is Fe2O3 + 3CO --> 2Fe + 3CO2
the first thing I notice, after looking at the original equation for a bit, is that you can add any number of iron atoms on the RHS without affecting any other elements. so this means we can fuck with the amount of Fe2O3 to get a total of two oxygen atoms on the LHS to balance the right:
(1/3) Fe2O3 + CO --> Fe + CO2 (oxygens balanced, carbons balanced, Fe not balanced yet)
now we can simply put a (2/3) in front of the Fe to balance the amount of Fe on the RHS:
(1/3) Fe2O3 + CO --> (2/3) Fe + CO2
now the equation's balanced, but not in whole numbers, so multiply everything by 3:
Fe2O3 + 3CO --> 2Fe + 3CO2
hope that helps.
[editline]10th February 2013[/editline]
[QUOTE=joe588;39538721]i can't get my head around chirality
[img]http://i.imgur.com/UNQjSs2.png[/img]
i thought it was top right and the middle but are they achiral? or neither . wtf.[/QUOTE]
nah, top right and middle have two identical groups attached to the central carbon atom. a chiral carbon atom has four unique groups bonded - top right has two CH3O groups, while middle has two CH3 groups. neither are chiral
the chiral groups are [sp]top middle and bottom left[/sp]
right cheers, makes more sense now. thanks man.
[QUOTE=joe588;39538721]i can't get my head around chirality
[img]http://i.imgur.com/UNQjSs2.png[/img]
i thought it was top right and the middle but are they achiral? or neither . wtf.[/QUOTE]
Bottom left and top middle
CH3 and H3C are the same thing and it's the same for the CH3O and OCH3.
[IMG]http://f2.braxupload.se/g8nybh.6ff812a5df.png[/IMG]
[editline]10th February 2013[/editline]
ninja :l
Sorry, you need to Log In to post a reply to this thread.
