Chemistry
For Chemistry Discussions
1,617 topics in this forum
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- 7 replies
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I need to draw a curved graph for some chemistry results, but can't find any software which isn't mathematical (and requires a function) or which offers a curve drawing element to it. I found one called labfit which lets you draw a single curve, but not multiple ones on the same graph. Any suggestions, or ought I to just give up and do it by hand?
Last reply by Mahdi7, -
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Anyone know a simple equilibrium reaction that I can use for a lab testing the effects of changes on equilibrium? All I can think of is acids and bases... and I don't know what I can use other than change of concentration. That kind of a lab seems really boring and obvious. Can anyone think of any good equilibrium reactions?
Last reply by Sandwich, -
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So we got a design lab in chem and all my teacher said was "write a lab investigating the properties of metals". I'm so pissed off because that's the most ambiguous task I've ever had to do. Can someone answer these questions? Should I investigate physical or chemical properties? How many properties? How many metals? I have no idea what would be reasonable. I'm thinking of comparing copper, lead, zinc, and iron. I should go for quantitative data whenever possible.. so I don't really know what to choose. Electrical conductivity is an easy one, but does that count as chem? I think physical properties are physics and I should analyze chemical properties. What does ev…
Last reply by Pod, -
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our teacher just assigned a design lab on water treatment and analysis.. but he didn't really explain anything.. We haven't really done many design labs before so im really confused and i dont know where to start. anyone have any ideas ? thankss
Last reply by Vvi, -
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Well the topic speaks for itself. But I also wanted to ask you comrads , if anyonw of you have done the industrial chemistry option. What do you think of it?
Last reply by KLSmash, -
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Am I finding the change of heat correctly? I am not so sure...please help! And i think i am totally off with the units...= = do we have to change celsius into kelvin and is the final answer j or kj Thx a lot >< Mass of the Salt = The Salt’s mass with the weighting boat – Mass of the weighting boat Mass of the Salt = (5.86) g ±0.01 – (1.01) g ±0.01 Mass of the Salt = (4.85) g ±0.02 Mass of the water = Volume of water x Density of water Mass of the water = (98.0) mL ±0.01 x (1.00) g/mL Mass of the water = (98.0) g ±0.01 ∆ Temperature = Initial temperature of the solution – Final temperature of the solution ∆ Temperature = (23.0) ℃ ±0.01 – (19…
Last reply by moneyfaery, -
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Well, I've recently created a blog to aid IB (and SAT II) Chemistry takers from all over the world. In the blog you'll find: Resources A periodic table Informational Videos IB Resources Chemistry Syllabus Chemistry Data Booklet Chemistry IB Notes These are notes I've been making as I go through the different topics on the syllabus at school. The notes: Have been made by a combination of information from different textbooks, teacher's notes and mark scheme answers All Topic covered are covered in the most thorough way possible Notes are made in a way an idiot could understand them. The information is very digestible and easy to understand. Contain step-by-step worked ex…
Last reply by Joey, -
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Hi I am doing a design experiment and I have so far decided to investigate the enthalpy change of combustion for ketones However, to be able to do this I need to know the theoretical value and I have no idea how to find it. Does anyone have an idea of what I could do and does the experiment look appropriate? I would be very thankful for any answers Capa...
Last reply by Capa, -
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We did a lab about how much ethanoic acid vinegar contained. Since the value stated on the vinegar bottle was in percent, I gave my answer in percent, but now I don't know how to state the uncertainty. According to our measurements, 6.2 % of the vinegar was ethanoic acid and the percentage uncertainty was 7.203 %. If I write 6.2 % plusminus 7.203 %, does that mean that 7.203 is "the percentage uncertainty of the percentage value"? Or should I write 6.2 % plusminus 0.4 %, like the percentage as the unit? I'm quite confused and the report is due Monday, can someone help me out, please? By the way, titration can only be used for acid/bases, right?
Last reply by Tilia, -
We're doing our chemistry IA right now and I'm officially out of ideas... The topics that the teacher told us to pick are Acids and Bases, Reaction Kinetics and Energetics. I already finished one, which I did reaction kinetics lab for...but I'm still thinking about the second one...and I have no idea what to do Do people have any ideas about Acids and Bases and Energetics? my teacher says that i have to change a variable...=.= i came up with how [buffers] affect pH..but it's too simple... HELP? please and thank you 10x ahead of time...
Last reply by dexter, -
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hey everyone, i have this lab to do and the problem is that when finding the uncertainty for concentration, i only have the uncertainty available for volume, not for moles since C=n/V. So, my question is: does my uncertainty for concentration equal the uncertainty of the volume or do i have to do something else??? thanks for any help ....
Last reply by IBdoc, -
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Does anyone know how to determine the physcial state symbols for an equation? ie: solid (s) liquid (l) gas (g) aqueous (aq) e.g the simplest equaiton possible: 2Mg(s) +O2(g) ------->2MgO(s) Is there an actual way of knowing? I missed a few chem classes last year (Pre-IB) due to sickness Please help me:) Thanks so much:)
Last reply by Stereoisomer, -
- 20 replies
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hi Guys check www.chemactive.com my personal website to get the latest lessons in chemistry in addition to exam papers in biology, physics and chemistry and more to come. feel free to leave your feedback.
Last reply by falu, -
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hey everyone, what is classed as a 7 in chem SL? thanks !
Last reply by CommeDesEnfants, -
- 12 replies
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I'm taking my mid-term today in Chemistry. My teacher is AWFUL and hasn't taught us much. She gives us tests then we raise our hand and she'll look over it to tell us which questions we answered wrong...Seriously. It's great for me, but I've been doing no work (cause oh yeah there's no homework either). Basically our exam used old IB questions--the stuff we haven't been taught. So, we're all going to do poorly
Last reply by heartworthy, -
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I'm doing a lab where we basically have to disintegrate calcium carbonate with an acid. We are allowed to use chalk rather than limestone or marble, but I was wondering if anyone had a better acid to use than vinegar or lemon juice :/ I was thinking something like sulfuric acid would be awesome to use, but it doesn't seem like something you can easily make in the lab. Any suggestions?
Last reply by heartworthy, -
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Hi guys, I'm doing a write-up on whether or not the type of carboxylic acid affects its rate of reaction with magnesium powder. Chemistry is far from my best subject... Could anyone give me a hand with the balanced equations for: Benzoic Acid +Magnesium C6H5COOH +Mg Tartaric Acid +Magnesium C4H6O6 + Mg Citric Acid + Magnesium C6H8O7 + Mg Would really appreciate the hand Thanks x
Last reply by ezex, -
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Ok, I have to do this design lab on esterification. I was thinking of doing something along the lines of [i]How does the length of the carbon chain on the alcohol used affect the smell of the ester made during esterification[/i]. However, the measurement of "smell" is not quantitative- so I guess it's not really a good title? I'm really stuck, I would really appreciate some help - either on approving / rejecting my first title, or helping me with a new one Merci merci
Last reply by Ashika, -
- 2 replies
- 863 views
Can anyone please explain to me stuff about the spectrums and stuff? I kinda get it but the whole thing is a bit confusing... ANy help would be appreciated Thx
Last reply by IBdoc, -
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I was in Chemistry after school exam revision today, doing MCQ about bonding. When we were going through it at the end of the hour, and we came across this question, where in the mark scheme it gives 'B' as the answer then it says if taught in spanish the answer is 'C'. So i thought, HUH?! the question was: Which of the following increase(s) for the bonding between carbon atoms in the sequence of molecules C2H6, C2H4 and C2H2? Number of bonds Length of bonds Strength of bonds A. 1 only B. 1 and 3 only C. 3 only D. 1,2 and 3 So we all answered B, because only number and strength increase and length decreases. Whereas in spain, their answers say that only strength of bond…
Last reply by Ashika, -
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Hi ive written a lab report in chemistry about back titration and the problem is that after having calculated the percentage mass of iron in a razorblad (which was the task) i have no idea what to write for my conclusion. i mean ur suppost to draw a conclusion based in your results and if ive already calculated what we were suppost to find theres not much more to do. (i got 83% iron in the razorblad btw) Any advice for what to write?
Last reply by KiwiFruit, -
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1.Hybridization i only understand the sp3 but sp2 and sp?? why does it only become a sp2 or a sp? 2.The shapes i get names from the book and other from past papers and other from online the whole angular and pyrimedal and stuff
Last reply by ezex, -
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What do u guys think is that best way to present a pH values for data presentation? im using office 2007..
Last reply by biochem, -
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I take both Bio and Chem HL for bio labs you basically have to put the uncertainity of the appartus such as plus minus 0.01g, as for chemistry its a little bit more complecated, the thing is i know NOTHING , my friend was telling something called literature value and discrimant can some one tell me what is needed EXACTY please??
Last reply by avrila, -
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Hello any ppl HLing in chem I really need help with delocalization of electrons my textbook explains it very badly and I have a test on bonding tomorrow. Please can someone explain this or point me towards somewhere I can find help Thanks
Last reply by dexter, -
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- 888 views
Hey I'm a newbie here, and I am in desperate need of some help with writing a lab report. To tell the truth I've always been bad with writing lab reports; in my old school I didin't have to write any, and even if we did we only had to write aim, method, result, conclusion and evaluation - the simple version. Last year - year 10, 10th grade, year 11 in NZ, 1st year of High School in Korea&Japan, whatever - when I moved to my current school, I don't remember writing any either. So [b]I really have no idea about all those stuff about variables and hypothesis and et cetra.[/b] Dependent variable, independent variable and controlled variable (was it?) - they all just co…
Last reply by deissi, -
- 4 replies
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Hi guys If you need IB chemistry mindmaps check the new page added on www.chemactive.com I hope you will find it usefull.
Last reply by wissamercy, -
- 5 replies
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Hello I want to do an exdended essay about whether food contains sis- or transfat. But yet I don't have any idea how to determine it. Could you please help me? Thank you for all answers Cheers Alfabeta
Last reply by Hedron123, -
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- 760 views
So, for the lab report in chemistry the teacher gave us a list of things that we have to include in it. It is divided in two parts where the first part is mainly observations, drawings, tables and answers to brief questions. The second part is the normal part where there is the purpose, procedure etc... Now the teacher told us that this lab report is assessed, but isn't it supposed to be the second part only to be a formal lab report? Are we allowed to include the first part?
Last reply by dexter, -
If anyone out there is good at giving online-style lesson I really am in need of some help. You see my teacher has a teaching style that doesn't seem to appeal with me, I guess my current mark in the 60s represents that. I am taking SL Chemistry and it's bothering me quite a bit. If anyone can offer help on basically all of the units, I would extremely appreciate it. I'm worried Chem will hinder me from being able to get accepted by the schools of my choice..so I'm desperate to raise the mark.. I've tried extra help and I've tried doing the homework questions, perhaps it is not the teacher and it's just me. I actually do try hard in Chemistry, its just the te…
Last reply by moneyfaery, -
Im a straight A chem student, and I was wondering if it would be in my best intrest to go into Chem HL. Everyone says its crazy hard.
Last reply by IBdoc, -
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does any know...where the best place is, find literature values for experiments, so your able to use them in your write-ups...??
Last reply by uummmdonuts1, -
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Well our school doesn't have spectrometers so we need to use a flow chart to find out what the ion content of the solution is. If it contains one of the following ionic compounds sodium chloride potassium chloride silver nitrate copper (II) nitrate copper (II) sulfate sodium carbonate zinc sulfate potassium sulfate I know if the aq solution is blue, then its copper, but if it isn't blue, how would I set this up? All help is greatly appreciated Thanks in advance
Last reply by IBSQUARED, -
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I have just done a practical on the affects on equilibrium of various factors. We were given background information about two equilibriums (chromate-dichromate equilibrium and the equilibrium between [Co(H2O)6]2+ and [COCL4]2-) and given Le Chatelier's Principle, and then told to identify the factors that affect the equilibrium and evaluate wheter the equilibrium adhered to Le Chatelier's principle. Considering this is all we were given, the prac I carried out involved adding acids and bases to the first equilibrium and recording the direction (left or right) in which the reaction shifted (I also tried to vary temperature to seee its effect, but there was none forthcom…
Last reply by luk3tm, -
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How can I tell what the color of a random chemical in a test without looking at it?It sounds really silly but that's what we have to do. Here is a Redox Reaction from a textbook: Pb2+(aq) + Fe(s) --------------> Pb(s) + Fe2+ (aq) Observation: Solution stays colorless, dark gray shiny crystals formed Why does the solution remain colorless? Shouldn't be green as Fe2+ is always green?? oh and another one: 2Fe3+(aq) + 2I- (aq) --------> 2Fe2+(aq) +I2(aq) Observation: Solution changes from yellow to deep red brown. OK so where did the yellow came from? (I thought all Fe3+ are orange brown) and how come it turned red brown? I know the Iodine turns brown …
Last reply by Stereoisomer, -
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So the other day I was searching for videos on chemistry on youtube. Unfortunately my chemistry teacher sucks and does not explain things thoroughly. Anyways, I came across this video on the mole concept: [url="http://www.youtube.com/watch?v=xiVweBpjXJo"]http://www.youtube.com/watch?v=xiVweBpjXJo[/url] I was amazed at how "chemguy" was able to make me understand the mole concept in about 10 minutes, something I did not understand when my teacher explained it. I immediately got interested and realized that "chemguy" had uploaded over 100 videos on youtube on chemistry! So from now on I will surely benefit from these videos! Just thought I'd let everyone know, so ev…
Last reply by Tilia, -
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im just stuck in one of my past paper homework. well it must be pretty easy for the IB1 and IB2 who have learned stoichiometry for chemistry already. well i dont know how to do this question, i just cant figure it out Question : How many oxygen atoms are present in 0.0500mol carbon dioxide. please can you show me the working as i just dont know how to solve it, thanks
Last reply by [m a a r i.], -
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If you measure the pH using a pH measurer (machine) - not pH paper, etc. what's the ± ___? percent error? on it... i hate error
Last reply by Max, -
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- 828 views
So I have one month to do my G4 in chem. Our topic is to investigate the causes (and/or) the cures for cancer. Any suggestions on how to develop my research?
Last reply by jjj, -
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Just out of curiosity, I searched the forum and there's no other thread like this...maybe except the biology one... anyway...I'm a bio/chem/geo student...so my picks are Human Biochem (apparently, it's 100% overlap with bio, whether it's HL or SL) Environmental Chem (70% overlap with Geo) i think i'm good to go... but which other Options are good to study...my main goal is easy to understand...and hopefully easy on exams..
Last reply by Solaris, -
How do you know what is constant in Boyles, Charles and Gay-Lussacs laws and how do you know whether to use those formulas, the ideal gas law formula or the combined gas formula? Thanks!
Last reply by starry-night, -
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i was given this task to design a experiment. I could have some modification from the experiment that has been made. but, i cant design it my own and i cnt find the existing experiment..somebody..please...very kindly to help me...im goin to submit this design very..very soon..
Last reply by jessie, -
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- 694 views
i very much need urgent help, in about 5 days, i need to hand in an experimental design for my chemistry topic, any possible suggestions? the topic is on the kinetic molecular theory of gas. my teacher wants me to focus on a macroscopic aspect, so meaning volume, pressure, temperature, etc, rather than a micrscopic approach to the topic. so, i would very gladly appreciate any and all help from you guys!! thank you in advancee!
Last reply by xsandralee, -
- 17 replies
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Next year I am taking IB Chem HL and I am kinda nervous because I heard it was REALLLY HARD! At first I was going to take HL Bio, but I changed my mind because I felt that bio would be boring. Anyways, how hard is this class if you have taken it or know people that have taken it? This year I took honors chem and I got a pretty good average (99) and I took the SAT II (720 - not that great but I will retake). What are my chances of actually doing well in this class, and what advice could you give me before I go into the class in september? Thank you sooo much!
Last reply by pretty_ah_boi, -
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everytime i come across a question like the following, i never know what to do so if someone could show me the steps taken to find values it would be helpful..thanks a 25.0 cm[sup]3[/sup] sample of 0.100 mol dm[sup]-3[/sup] hydrochloric acid was placed in a concial flask, and 0.100 mol dm[sup]-3[/sup] sodium hydroxide is added until a total of 50.0 cm[sup]3[/sup] had been added. Sketch a graph of pH against volume of NaOH(aq) added, clearly showing the volume of NaOH (aq) needed for complete reaction and the pH values at the start, the equivalence point and finish.
Last reply by booji, -
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does anyone know any procedures to quantify and detect chamazulene? its for my chem ee
Last reply by booji, -
Why do some form precipitate?
by Guest The X- 7 replies
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If I add regular table salt to water, it dissolves in the water. However, if I add Silver Chloride to water, is just precipitates. Why the difference? I've been discussing this with my chemistry teacher, and it seems that she can't remember, having only just accepted that "that's the way it is". But we're both curious now, and that's why I'm asking. We've considered both electronegativities and ionic radius, but cannot seem to find an answer. An other interesting question I've got for you, is why HCl dissociates completely. Why should not CH[sub]3[/sub]COOH do so? Does CH[sub]3[/sub]COOCl (Chlorine Acetate/Ethanoate) do so?
Last reply by booji, -
- 3 replies
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Could anyone explain the formula for enthalpy change, because my chemistry teacher has us really confused, we even noticed that shes just understanding what she is explaining when she does the explaining, but I got some info from the net so I just wanted to know if someone could check it for me Enthalpy change= enthalpy of products - enthalpy of reactants the enthalpy energies are supposed to be negative or positive? And is there any relation here with the enthalpy diagrams? thanks
Last reply by booji, -
- 6 replies
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Anyone care to answer my questions on peak splitting for H NMR? I'm very confused as to what exactly happens..for example, the textbook gives the example of ethanol. The CH3 group is split into 3 peaks because of the neighbouring CH2 group, which has 2 hydrogens. Ok, I'm good with that. But how come the CH2 group isn't affected by both the OH and the CH3 groups since it's in the middle? And why is the OH group only a singlet and unaffected by the CH2 group?
Last reply by booji, -
- 5 replies
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Can someone please please explain the mechanisms part of organic chemistry to me? As in addition reaction and all that jazz.
Last reply by booji,
