Chemistry
For Chemistry Discussions
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Anyone have a literature value & source for the order of reaction of iodine in the halogenation of propanone? Full equation is as follows: I2(aq) + CH3COCH3(aq)+H + (aq) --> CH3COCH2I(aq) + I-(aq)
Last reply by Drake Glau, -
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I did not fail chemistry as you would expect, quite the opposite. I am an IB diploma candidate and I am considering my hl to be chem, as for the only reason I would go to this extent of having took chemistry for so long. Is 3 consecutive years of chemistry appealing on transcripts? biology in freshmen year(9th grade), chemistry (regular, 10th), chem sl(11th), chem HL(upcoming senior, 12th)
Last reply by daxx, -
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Hi, I just wanted to ask if it is possible that a question asking for the description of one industrial process occurs on the final exam. And if yes, how could it be stated? The reason I ask is that one could write a one hunder page essay on this topic so I just don't know how much I should learn about it. Thanks
Last reply by daxx, -
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Hello We did a lab in chemistry HL about the chromatography of M&Ms. I have found the Rf for each M&M thus far, but what I am missing is the possible colorants... which I need to find on the Internet and I have had no luck whatsoever with that! Do you have any suggestions or websites which can help me find the colours that match my Rf, please? Thank you so much
Last reply by Keel, -
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My Chem class is having a major dispute at the moment over what the formula is for bond enthalpy change!! Any one like to make an input??
Last reply by Drake Glau, -
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What are limitations and weakness? I mean, my teacher never told us what we were supposed to handle within this points and I am lost! I need to hand out the laboratory and the draft for my EE on tuesday, I have noo time
Last reply by Emmi, -
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So basically the title says it all. I kinda need to know the trend in the standard electrode potentials chart on table 14 I think in the data booklet. Is it stronger reductant at the top of the right hand side and stronger oxidant on the bottom of the left hand side? so confused....
Last reply by Drake Glau, -
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Because of budget cuts, our teacher needs us to figure out what we're doing for our IA labs now so that she can order the materials before we run our of money! But I have no idea what I'm going to do, I only have one lab design right now. Any ideas for a biochemistry lab? or any kind of chemistry lab besides titration? (I'm already doing that) how many labs do we design anyway?
Last reply by Drake Glau, -
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Hello, I'm curious about studying options for the HL chemistry exam. Are the topics and details that's written in the syllabus details (http://www.lancaster.edu.mx/lancaster/lancaster_news/img_affiliations/IB_Syllabuses/IB%20Chemistry%20syllabus.pdf) enough for the ib exam? I'm not sure because the textbook has more information than what's said in the syllabus details =/
Last reply by Drake Glau, -
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Hey guys, So I have a lab I am currently working on (at the moment I am on the calculations) that has me stumped... My lab is about how the mass of CaCO3 affects the enthalpy change of this reaction: CaCO3 + 2HCl -> 2NaCl + CO2 + H2O. I have carried out all of my experiments using 5 separate values for the mass of calcium carbonate (i used a temperature probe during the experiment so i have graphs of the temperature change for each of them) but now i'm confused... usually i have to compare a theoretical result to an experimental result... but I don't know how I actually find the theoretical result in order to compare it to the value of the enthalpy change for my rea…
Last reply by ibquestions, -
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Hi I'm currently having my internal assessment for chemistry SL at the moment. The topic our teacher has given us is "study the energy of various fuels". My lab design is going to be about testing the HHV values of different states of hydrocarbons but my problem is that it uses a bomb calorimeter. Would I have to explain within the instructions how to use the bomb calorimeter? And is it even a good lab in your opinion?
Last reply by Keel, -
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I feel pretty prepared for the SL Chemistry test...except that I've never actually seen one, and have no idea what to expect! Would any of you mind explaining what each of the papers is like?
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Working through some past Paper 1s and a couple questions make no sense to me! Any clarification to any (or all) would be most appreciated! Here they are: The temperature of a 2.0 g sample of aluminum increases from 25 °C to 30 °C . How many joules of heat energy were added? (Specific heat of Al = 0.90 J g−1 K−1 ) A. 0.36 B. 2.3 C. 9.0 D. 11 (Answer: C) Separate solutions of HCl (aq) and H2SO4 of the same molar concentration and same volume were completely neutralized by NaOH (aq). X KJ and Y KJ of heat were evolved respectively. Which statement is correct? a) X=Y b) Y=2X c) X=2Y d) Y=3X (Answer: B) Thanks in advance
Last reply by Drake Glau, -
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Hey guys, which SL chem options are the easiest to learn on your own in one night? I have to learn discrete math for monday's math paper 3 and I have to read the books for english paper 2 on tuesday so I really only have monday night to study the chem options and I don't know anything about them. I took physics and economics and I know there's a bit of overlap in the chem options with other subjects so anything related to those might be alright, and I really hate bio so nothing related to bio please but other than that I don't have much preference. I just need something I can learn in one night that's straight forward. Thanks guys, really appreciate it.
Last reply by dogmatichurricane, -
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does anyone have any ideas for an electrochemistry design lab??
Last reply by Alex1307, -
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I was just wondering what is your favorite IB chemistry topic. Personally, I love organic chemistry and acid/base! I find these topic fascinating What about you guys?
Last reply by Simon, -
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If the % efficiency of calorimeter is over 100%, does it mean that it is more efficient? Or is it not, because it got further away from the literature value. Thanks
Last reply by Keel, -
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I'm in year 11 but anticipating Chemistry and it's my last year of it. The November exams didn't go too well for me and I'm sitting between a 4 and 5. I'm kind of struggling in it and don't know if I should repeat it after this year and do it HL instead. Any suggestions?
Last reply by Internationalbaccawhat, -
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Hi How long does vinegar need to be exposed to the atmosphere for to see a change in concentration of CH3COOH? Is it a matter of hours or days? Thanks!
Last reply by Drake Glau, -
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Would anyone happen to know of somewhere that I can find past SL chem exams that I can use for practice? (Answers included would be extremely helpful.) If they aren't official past IB exams but are still the same format, difficulty, etc, that would work as well. Thank you very much! Edit: Ack, I just saw a thing that said no past paper distribution, so that's out! However, do you guys know of any other resources that I might use? Thanks again!
Last reply by sillymissrachel, -
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Hey! What do you think would be easier for someone who does not take physics or biology for a chemistry SL option: industry or meds? We did Biochem and Organic in class and although I got good grades on the tests I didn't like them and can't remember much of them anymore so I figured I'd just learn some easier new ones. I did environmental which was OK but I can't seem to choose what to choose as the second. (There is of course the option of just learning biochem again.) I heard industry is one of the easiest and the questions are likely to be easy but at the same time some of drugs&meds is stuff you know anyway... So what do you recommend?
Last reply by nuka, -
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Does it hurt my grade? I know it is the best to put them into one table but there is some complexion for me to do that. So is there any aspect in DCP or Conclusion/Evaluation where it says that I can't do 4 different tables for raw data? OH and do I have to put the heading for each table? Do I have to label like Table 1, table 2, etc? and Does the heading have to be descriptive (e.g. Measuring blah blah blah) can it be just like Masses of blah blah blah? If I have to be descriptive, what kind of heading do I have to use for processed data?
Last reply by IB-Adam, -
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A quick question............are esters part of the Ib chemistry Sl syllabus? because my teacher basically skimmed over that section?
Last reply by Sandwich, -
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My chemistry teacher gave us a "prompt" that provided a situation and gave a materials list and even told us what to test. She said this is our actual IA and is making us do it in class so that we do not "cheat". So basically, we were given 3 days to do the design portion of the lab in class. And she told us that we're not allowed to talk with anyone in class while doing it either. Is this the proper method for administering a Chemistry IA? Because I also have IB Biology and the teacher for that class actually assigned the IA as homework (which is how I think it should be). Any feedback would be appreciated. Thanks.
Last reply by dessskris, -
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Hi, in my chemistry class, I'm doing a measuring lab, figuring out which equipment is the most accurate among graduated cyllinder, burette, graduated pipette and volumetric pipette. And I'm assessed on DCP and conclusion. 1) For presenting raw data, can I put 4 different tables like this (only one of them is presented below), not just one big table? Because if I put them all in one, I don't know how to handle the uncertainties... It just doesnt fit. Table 4: Volumetric Pipette Volume of water in conical flask (ml) Masses of the conical flask and of water (g) 0 175.433 25 200.75…
Last reply by Keel, -
Hello chemists and perhaps biologists. Biochemists will probably be able to offer advice on this. I'm currently doing Modern Analytical Chemistry (Option A) and Medicines and Drugs (Option D) The MAIN problem is, i cannot for the life of me grasp Option A. I have tried and tried and i just can't do it. IR spectroscopy/NMR spectroscopy/AA spectroscopy/UV spectroscopy is all too dull and i don't understand it AT ALL. Today i was reading through my textbook and i saw that i knew more on the Human Biochemistry (Option B) (As i also do Biology Higher) than i do Modern Analytical Chemistry! I know that in the REAL exam you can choose which option to do. Should i revise the…
Last reply by Bianca Gill, -
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Hey people! My Design Lab 2 Prompt is: Investigate a factor that distinguishes salts. Here is my question: How is the yield of Sodium in a Sodium Halide affected by different halides?
Last reply by Drake Glau, -
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Hey guys, first post here Chemistry teacher just left us a practical concerning intermolecular forces and physical properties. The practical was divided into 3 aspects: 1. Dipoles: we open the burette and a stream of the following liquids will come out, then we put an ebonite rod near the stream and observe the results hexane, water, propanone, ethanol and tetrachloromethane. Why were some substances repelled from the rod? 2. Solid's solubility: prove the solubility of 5 solids on water and hexane: NaCl, iodine, urea, wax and SO2 Why were some of the solids dissolved, why were some not dissolved? i got to comment on their ionic and covalent nature of the solids. 3. liquid…
Last reply by ervo, -
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Hello, My questions is regarding the standard on temperature and pressure. I'm uncertain on which ones IB uses. I have read in the Pearson Baccalaureate HL Chem, it says the standards are: STP - 273K at 100kPa RTP - 298K at 100kPa However, my teacher tells me it's: STP - 273K at 101.3kPa (1atm) SATP - 298K at 100kPa Which one is right? Or are they both wrong? Thank you!
Last reply by ervo, -
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I'm looking for some quizzes/tests that are related to Oxidation and Reduction(for IB). Can anyone help me?
Last reply by anonymous4, -
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Hi, I would like to know a method to measure the rate of reaction of each of the following reactants; AgCl, AgBr, and AgI. The reactions has to be unimolecular, that is in this case, when these reactants are exposed to light forming Ag+Cl/Br/I. I had the idea that for each measurement, I give the silver halide light for a fixed amount of time. Then I separate the silver formed from the unused silver halide and measure the weight. But then I would not would not be measuring the rate of reaction that accurately, or not even at all. Do you have any good methods to share? It would be best if concentration or mass vs. time graphs could be made. In school we have those program…
Last reply by Keel, -
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I really want to do well in these labs, but my teacher is just crazy and I'm not a good chemist...n I study in Chem SL (forced to change to SL from HL:[ ) So I need to do a chemical reaction rate design lab...I am completely clueless. I mean, I know what the factors could be, temperature and concentration etc. I am really really stuck :[ Please help.
Last reply by dreamingonacloud, -
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Last year (in 10th grade) I LOVED chemistry; furthermore, I was good at it, to the point that I considered HLing. It just made sense to me, and with a small amount of studying, I could easily understand (and ace) everything. This year, not so much. I read and reread my notes, I go in during lunch at least twice a week to review things with my teacher, I do ALL of the homework, I study old tests, I've made flashcards, I've gotten old tests from my teacher to work through...and nothing seems to stick. It just doesn't make sense to me! I'm definitely planning on SLing, since I think that trying to HL would just be one huge frustration. So, my question is: What tips do you al…
Last reply by nuka, -
Hey guys! I was wondering what I can use instead of a fume hood for my experiment?
Last reply by Keel, -
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I am doing a lab report on how the concentration of hydrochloric acid effects the amount of hydrogen gas that is produced {in this reaction only: Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g) }. I used the following concentrations of hydrochloric acid: 0.100moldm-3 1.00moldm-3 3.00moldm-3 5.00moldm-3 6.00moldm-3 As hypothesized, more hydrogen gas was released in higher concentrations of hydrochloric acid then lower concentrations... except no gas at all (at least none that was measurable using the method of downward displacement of water) was released for the 0.100moldm-3 concentration and I can't seem to figure out why this happened? It could be because of human/random error…
Last reply by Drake Glau, -
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Hey So, my experiment investigates how the concentration of hydrochloric acid effects the amount of hydrogen gas that is released: Zinc + Hydrochloric Acid --> Zinc (II) Chloride + Hydrogen I used the method of 'downward displacement of water' to help me obtain my results, and now I need to write up the lab haha but I always seem to have difficulty writing up the principle of method/measurement and I was wondering if I could possibly get some help? As well as this, what are aspects that I need to include in my introduction(or background information) section? Any help would be greatly appreciated Thank-you
Last reply by larry, -
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Hello! I am doing the first year of Chemistry HL. I don't understand how you do this question: A certain element has the electronic configuration 1s2 2s2 sp6 3d10 4s2 4p6 4d6 5s2 Which oxidation state(s) would this element most likely show? A. +2 only B. +3 only C. +2 and +5 only D. +2, +3, +4, +5 How do you figure it out?
Last reply by Drake Glau, -
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hey I have a small problem. tomorrow I am having lab about checking the amount of CaCO3 in eggshells but the teacher told us to check the percentage of this CaCO3 before lab as we will know what results should we expect. does anyone know something about it and want to help me?
Last reply by Keel, -
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Hi everyone, I'm doing a lab on determining the rate expression for the iodine clock reaction (i.e. mix potassium iodate with varied concentrations with starch), along with the rate of reactions for each level of concentration. I'm wondering what type of stuff should I mention in the conclusion. For the scientific explanation, I was thinking about writing about the collision theory and rate expressions. Am I missing anything? For the error analysis/improvements, I was going to write about the consistency in mixing the two solutions together, cleanliness of test tubes, and explaining the large error bars (for my data specifically). Are there any other suggestions/improvem…
Last reply by Keel, -
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So my teacher says it's really hard. Is it really as hard as she making it sound or? Any tips to doing well throughout the chapter and some extra things I can do in order to do well?
Last reply by Mahuta ♥, -
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My teacher gave is giving us a design lab and all he said was that you would be given an unknown acid. I know how to figure out the unknown acid, but that's not a lab. I need some ideas for a lab to do after identifying the acid, or maybe even without identifying it. I know there are lots of possibilities that I can do with that, but my teacher requires that we do a lab on something we can't just look up. Although this standard is of course IMPOSSIBLE since you can look up just about everything, please help me brainstorm some lab ideas for the acid that are a bit less "obvious" Can anyone help?
Last reply by Drake Glau, -
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Hi everybody. I have Chemistry SL mock exam tomorrow and I am solving some past exams. In May 2003 there was a question about polyesters, but I really don't remember studying them. I know we have to know about polymerization of alkenes... So, are polyesters part of the SL syllabus? Best regards.
Last reply by Fermoselle, -
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I did the Hydrogen Peroxide Variant of the Iodine Clock Reaction and measured the effect of temperature on reaction rate. I'm more or less done with my Lab Report, but I'm missing what I feel are essentials and I don't really know how to add them. For one, I don't understand how I'm supposed to "manipulate". I have the times the reaction took to occur at 5 different temperatures, and I've graphed it, but that doesn't give me as much as I'd like to work with. I don't really know what I'm supposed to calculate other then the averages for trials, and that makes me feel like my report is strongly lacking. I also don't know what I'm supposed to use for my evaluation. I don't k…
Last reply by Drake Glau, -
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So i performed 3 trials of an experiment and i recorded the following data: 17.12 cm +/- .1 cm, 17.73 cm +/- .1cm, 17.42 cm +/- .1 cm I need to take the average of this data, but I'm unsure of what to do with the uncertainties.. do you add the uncertainties together so my final average ends up to be 17.42 cm +/- .3 cm?
Last reply by Drake Glau, -
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I need someone to explane exactly and not just copy the sylabus on here, how to write a perfect lab report. one that i can get better than a 5 in! I REALLY NEED THIS HELP! An uploaded example would help A LOT! as well!!!
Last reply by darkwatch218, -
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Hello all I have been sick lately and thus the ability of my brain to contemplate scientific reactions (such as the one below) has gone down the drain... I just can't figure out how to do this and would greatly appreciate some help if anyone is willing to offer How would I scientifically measure the following? How does the concentration of HCl (in the following reaction) affect how much hydrogen is produced? Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g) Thank you to all those who are willing to help Being sick sucks Have a nice day
Last reply by darkwatch218, -
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First of all, thank you very much for reading! But don't stop, please comment-HELP ME! So the thing is, we're down to the business end of our IAs in our school. Every thing's going very smoothly. But I have major problems in Chemistry IAs, specifically in DCP and CE. We've done 40 hours of lab work and I don't think I can do anymore of it. Yet, if it is necessary, I can definitely get my teacher to allow me to do some more labs. Sorry for the circumlocution; I'll get to the point right away. None, I mean "NONE" of our experiments allow for plotting graphs. I mean meaningful graphs whose gradients or intercepts can be used to process data. Some experiments didn't even all…
Last reply by Nishad Potdar, -
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Hello everyone, Im doing a design lab on "How does temperature affect the reaction rate of decomposition of hydrogen peroxide?". The chemical formula is 2H2O2(aq) --(catalyst)--> 2H2O(l)+O2(g) I thought of controlling the temperature by placing the vessel in which the experiment will take place into a water bath. Since its exothermic, cold water will be constantly added into the water bath to keep the temperature constant(the temperature will be monitored). But there are several problems with the method because the lower part of the vessel where the reaction is taking place(im assuming) is cold, its the top part where oxygen gas is given off that is very very hot, so…
Last reply by natalia92, -
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ahhg ok i will not panic. ok so will anyone be so kind to help me with this topic. i'm thinking about investigating whether homologous series differ in reaction rate...so this also involves kinetics..which i am not very good at. i was thinking about doing a bromination but my BIGGEST PROBLEM is measuring the reaction rate. help anyone? should i completely change my idea? i guess if i'm desperate i'll do an investigation about their physical properties..but yeah :/
Last reply by Keel, -
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How much does the size of a drop from a burette vary with concentration of salt? I'm guessing a higher concentration would mean larger drops, but I'm not sure how much. 250 500 750 0M 11.24 22.83 33.56 1M 11.00 22.29 34.01 2M 11.01 22.15 33.13 3M 11.75 22.92 34.11 4M 11.59 23.9 33.99 I have these stats, the left side being concentration of NaCl and the top being the number of drops that have fallen (yeah I counted them all, ugh) and it's kinda all over so I need to doctor it up a little and I'm not sure what an optimal amount of doctoring would be.
Last reply by Drake Glau,
