Chemistry
For Chemistry Discussions
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I have come up with improvements like doing it in the same atmospheric pressure and environment, other improvement include carrying the dissolving part in a conical flask to reduce chances of spitting. Can someone give me some other advices because all I can come up with at simplistic limitations. Please help.
Last reply by Mahuta ♥, -
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Hi there, At school I am designing a practical experiment to investigate factors the influence acid rain. I have decided to investigate the concentration of acid rain. The problem is that I don't know if the method in which I am investigating it will even work - hence I am asking you, the experts, on your opinion. I have 4 ways that I am considering investigating it and they involve measuring the volume of the gas produced. The acid I am using is sulfuric (sulphuric) acid with concentrations of 1mol/L, 2mol/L, 3mol/L, 4mol/L and 5mol/L. The substance I am using to reaction is calcium carbonate. So these are my ideas: 1) React 1gram of calcium carbonate (powder) with …
Last reply by Lance H, -
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HL chemistry... why why i took this course... well anyway i need to determine the order of reaction with respect to H2O2 for the reaction with KI in acidic solution And i have completely no idea how to calculate this. My teacher asked for help explained me that though I had 6 for the first semester now I became completely brainless and she is not going to waste her time on such student. Encouraged by the teacher I tried a few times took three different tutors and still nobody can explain me how to do this. I begin you please help me
Last reply by Vahl, -
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I was never really good at the data analysis section of science IAs. Here are the basics: Question: What is temperature’s effect on the “blue bottle reaction” rate? Hypothesis: If temperature affects the blue bottle reaction rate, then high temperatures would accelerate the rate of reaction more than the low temperatures would, because high temperatures would cause the particles in the solution to move faster, which would increase collision frequency. Indep variab: Temperature - celsius [test groups are control, 30, 40, and 50] Depen variab: Reaction rate - seconds I have dextrose, NaOH, and methlyene blue (serves as an indicator; AKA it changes the solution blue when …
Last reply by I fail at failing, -
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I need to design an experiment which demonstrates equilibrium. I donot need a quantitative analysis. a qualitative observation woould suffice.... plzzz i am basically a bio student so i'm not that much into chem.....
Last reply by Baba Ambedkar, -
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Hey guys!! OK this is SO STUPID... but we had a practical in class and I recorded data etc etc and i found this: Mass of beaker used: 9.6190g Do you think a beaker can be 9.6190g? Or did I place the decimal place in the wrong place? I am pretty sure the numerals are correct. Im just a little skeptical. Thanks
Last reply by Charizard, -
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Okay, well I'm not doing so well in the class I was wondering if anyone had any advice on how to study for it? Or if there are any websites that might help me do better? Sometimes, it's not that I don't understand it's just I get confused really easily; at first I was doing really badly, then it got better, but now (after getting a test back) I'm not feeling so well anymore Should I take a summer revision course? (are there any that you guys recommend?)
Last reply by Charizard, -
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Hi guys, my chemistry teacher has been throwing us a lot of IA's lately and she keeps going on about how we arent analysing our data well enough. I know that you are supposed to use the experiments repetitions to find averages, SD etc, and then usually go through a test of significance like the t-test. But, for a typical chemistry experiment there wont be many test repetitions (only 3 for my last one ) so its impossible to do a significance test (as you need 10 or so).. My question then is, what have you all done that is considered 'data analysis' ? I am stuck for ideas besides mean/SD/percentage with my crappy repetition number. If anyone knows any other tests or anyth…
Last reply by Hedron123, -
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So, I am designing my own procedure on how the concentration of substances affects the voltage in a voltaic cell. I am given two substances: 1) CuO4S.5H2O and the molecular weight is 249.68g/mol. 2) Mg(NO3)2.6H2O and the molecular weight is 256.41g/mol. I have chosen my dependent variable to be the voltage and the independent variable being the concentration of solutions. I have to investigate how the change in the concentration in one of the substances affects the voltage. I am told to find out what mass I should be using in order to come up with different concentrations to use...I am confused about this bit...how do I find out which masses to use?? Oh, and I am going t…
Last reply by Sandwich, -
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Hi, I was wondering if anyone who studied this option could advise me on whether or not to take it. My teacher usually does Medicines and Drugs along with Human Biochem, but I really cannot stand biology, and she is letting us decide if we want to study another option by ourselves. I realize that FC is still in many ways related to biochem, but my question is, would you recommend it for self-study? It seems easy enough to me...
Last reply by Hedron123, -
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I have to do a chemistry IA about RFLs, but I'm not in bio and I have no idea what they are. They're not listed in the biology textbook index and when I try to google it, all I get is "Robot Fighting League". I tried googling it with words like "science" and "biology", to no avail. Can someone just tell me what it stands for at least so I can more adequately find information about it? Thanks so much
Last reply by Sandwich, -
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Hi, In chemistry, we are soon starting our design experiment. There are a few options to choose from and one of them is one that we choose ourselves. I just wanted to know what are some fun design experiments you have done in your school.
Last reply by Saransh, -
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We have to design a chemistry lab report and the topic is bonding...What are some good ideas? I am in Chemistry HL.
Last reply by JaneDoe93, -
Investigate the effect of one factor on the experimentally determined pKa of a weak acid.
by fat+dog- 2 replies
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Does temperature change the pKa of acetic acid? I heard that temperature kind of breaks down the acetic acid or something. Is that true? Can I use the titration method for this prac?
Last reply by Mahuta ♥, -
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Hey everyone, what are your thoughts on this option fo hl chem? and what Options did everyone end up doing and what would you recommend? any feedback would be nice thx
Last reply by Mahuta ♥, -
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Hola! I have a problem. I designed my experiment on finding amino acid isoelectric point from titration curve. Well yes, I have a titration curve BUT the problem is that I have curve - pH againts time while I need curve - pH against amount of H+ ions. Unfortunately amino acids is no longer possible to get and I cannot repeat the experiment again. SOOO, can anyone suggest me what can I found and design and report on my experiment report from curve, which I have?!!? PLEASE HELP MEEEE
Last reply by Mahuta ♥, -
- 16 replies
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Hey I'm just curious as to see what you people do to do well in Chemistry. Do you use any resources or do you just follow the classes and rely on that soly? I'm wondering what I should be doing and giving priority to in terms of hard topics or other things. Did you use any revision guides, did you use any question banks. What do you think is necessary in order to do well in Chemistry and also enjoy the subject. Thanks in advance.
Last reply by Mmaatt, -
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Hi can anyone explain how dipeptides and tripeptides form? The notes I were given aren't really clear...
Last reply by Mahuta ♥, -
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Hello everyone, I need your help and advise on a problem I am facing. I will be starting the IB course next year summer and I don't know whether to choose chemistry or not. My first choice for uni is to go into medical school. I love biology but i dislike chemistry. I always ask myself that do i really want to go into medicine and do chemistry for a longer time if i dont enjoy it. Will chemistry be a nightmare for me in IB? I am thinking of doing Biology, Maths and Chemistry at higher level but will these choices be too stressful for me to handle. I wouldn't want this to affect the points i get at the end of the exams. So please help me out!
Last reply by Miya0o0o, -
- 10 replies
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My chemistry is so demanding, but i'm no afraid of keep going. Anyways, someone can give a link or a doccument of the 2009 syllabus of chemistry SL, to know what and what not study. And some advice of what option to use, I thought about medicnes and drugs because I watch a lot of house, grey's anatomy, private practice, ER,Scrubs and Mental. And I've read a lot of medicine book thanks to that and I'm planning on becoming a doctor... can someone orient me please, or I just stick to enviromental ?
Last reply by sweetnsimple786, -
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Hey guys I'd really appreciate it if someone could help me with this question. Question 1 100 cm 3 of ethene, C2 H 4 , is burned in 400 cm3 of oxygen, producing carbon dioxide and some liquid 2. water. Some oxygen remains unreacted. (a) Write the equation for the complete combustion of ethene. (b) Calculate the volume of carbon dioxide produced and the volume of oxygen remaining. Question 2 The combustion of 45.92 grams of a compound which contains only C, H and S yields 70.77 grams of CO2 and 7.24 grams of H2O. What is the empirical formula of the compound.
Last reply by sweetnsimple786, -
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Ok so if someone could help me i would seriously appreciate it. Im in Chemistry Sl and i need to design an experiment to show an aspect of neutralization, and it can't be super simple. so if someone could give me an idea that would be amazing. Thank you before hand
Last reply by YdidIneedThis, -
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My teacher hasn't really had very many 7's, but I'd really like to shoot for it, even though I'm not too hot with the sciences. Any precautions you'd advise me to take to prepare for the SL exam in my naive hopes? Perhaps a formula? lol. I know, study my arse off, but, any secrets?
Last reply by Sandwich, -
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Will the reaction between potassium permanganate and iron(II) chloride happen and why? Is it exothermic and if so will the temperature change be slow and measurable and why? Is measuring the temperature change best way to detemrine the rate.
Last reply by kankeel, -
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Hey guys! I was reading through my textbook today and I found a worked example that got me very confused... What mass of propanol must be burnt in excess air to produce 10000 kJ of energy according to the following thermochemical equation? 2C3H7OH + 9O2 ---> 6CO2 + 8H2O deltaH = -4034 kJ/mol So this seems simple enough. But the worked solution states: From the equation, 2 mol of propanol yields 4034kJ of energy, so x mol of propanol yields 10000kJ of energy. WAIT WAIT WAIT. the deltaH value states -4034 kJ PER MOL. then why does 2 mol of propanol yields 4034 kJ of energy? Shouldn't it yield 8068 kJ of energy intead? I think I must be wrong because that example ori…
Last reply by Stereoisomer, -
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I was set a task to design an experiment to investigate one factor that affects the oxidation of iron(II) to iron(III). Can someone possibly give me some clue as to how i should start thinking about it because i am confused. Some comments please?
Last reply by kankeel, -
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I'm designing a practical experiment on the Vitamin C content of commercial tablets. But I need to formulate the research question in such a way that it is an investigation, not a simple quantitative "determine vitamin C content of..". I'm guessing, it'll have to be some kind of research into how the content varies with something. But what could be that something? Or any other suggestions? HMM.. thanks!
Last reply by Pirat Havelund, -
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alloo peeps..anybody help me please??? this is the first time i am doing my chemistry laboratory report for DCP analysing. so..i've no idea on how to do the report base on title " determination of the chemical formula of a hydrate" so..i do really hope that somebody could lend me some ideas so that i'll get some hint on how to make it easier..please...... how to calculate the mass percent of water and the chemical formula of the unknown hydrate???? thanx guysss
Last reply by master135, -
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I know the biology one is pretty good. Hows the chem one HL? thanks guys
Last reply by Tilia, -
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Hey im just going over some past papers and I just have a few questions I can't answer... Ill just post them here and if someone could help itd be awesome. 2. Which sample has the greatest mass? A. 6.02 x 10^23 molecules of hydrogen B. 5.0 mol of neon atoms C. 1.2 x 10^24 atoms of silver D. 1.7 x 10^2 g of iron 4. Which sample of nitrogen gas, N2, contains the greatest number of nitrogen molecules? A. 1.4 g N2 B. 1.4 dm^3 of N2 at 1.01 x 10^5 Pa and 273 K C. 1.4 x 10^23 N2 molecules D. 1.4 mol N2 My teacher didn't give me a markscheme so im trying to make one...
Last reply by charco, -
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Hi! I do chemistry HL and in exams i always get the order of reaction correct but i don't get the reason correct. So could somebody please help me understand the reason for obtaining a certain order of reaction. Thank you. I have attached a past paper. I was doing the first question.
Last reply by Parami143_Kella, -
- 2 replies
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Hi..!! I am doing my chemistry kinetics lab report and I need the literature values for the rate law and rate constant for the reaction between KI( 0.01 M) + KBrO3(0.04 M) + HCl(0.1 M) . Can anyone help me with this?? I couldn't find it anywhere.
Last reply by Tilia, -
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So, basically, I'm looking for revision sites that cover all the Chemistry HL topics.... Anyone know any good sites??
Last reply by Peachez, -
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Okay, so I've been struggling in chemistry all year.. I'm in HL right now but I'm switching into SL next year. My problem is that I have one final experiment that I have to do, and I am completely and utterly lost. Can anyone help me with my error calculations? (PS: I did a titration) example: pipette = +/- 0.06 mL graduated cylinder = +/- 1.0 mL Ca(OH)2 = +/- 0.001 g titration (HCl mL difference) = +/- 0.4 & PS: I'm having trouble figuring out the molarity of the Ca(OH)2 I dissolved 0.1g of it in 100mL of water and titrated that with HCl, trying to figure out how stirring affected an equilibrium constant.
Last reply by Tilia, -
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Hey, I wanted to ask whether anyone knows a really good book for Chemistry HL. I have the Oxford University Press Study Guide and the Course Compagnion, but I don't find them all that good. I recently bought the new Heinemann book for Biology HL after being fed up with the Course Compagnion which is usually really good... Does anyone have any experience with the chemistry book of that publisher or any other book they can recommend? Thanks a lot!
Last reply by dexter, -
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Does anyone have these? http://ibchem.com/download/index.htm If you do please share Thanks.
Last reply by Eternalx, -
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We did a lab where we were supposed to find the order of reaction of the reaction between magnesium and hydrochloric acid from measuring the volume of gas formed vs time. I've drawn a graph, found the logarithmic function and now I need to find the initial rates. I know that the initial rate is the initial gradient, but what's the best way of finding it? I haven't learned calculus yet, so I'm not expected to use derivatives. I thought about treating the first and second measured value as a straight line and hence find the slope, but that will be over a comparatively large time period. Is it better to use the function to interpolate a value inbetween and thus get a smaller…
Last reply by Tilia, -
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Hi everyone Im really struggling with Quantative Chemistry, when i see questions such as when Xgrams of this is added to Ygrams of that what mass do you get? or when they includes percentages of elements in compounds. I was wondering if anyone knew any site to revise these types of questions?
Last reply by Damon, -
- 3 replies
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Although I don't take chemistry, this question got me hooked. Calculate the molarity of an HCl solution if 25.0 mL of the solution is neutralized by 15.5 mL of 0.80 M NaOH I took this in IGCSE last year but forgot everything about it, and it is really frustrating can anyone help me solve this? I forgot all the steps!! Thank you
Last reply by HJ:), -
- 4 replies
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[color="#0000FF"][font="Comic Sans MS"][size=2]some help with chemistry..... a checklist for write-ups, covers design, data collection and processing, and conclusion and evaluation- D, DCP & CE. and a practice kinetics test my class sat a couple of weeks ago. HL and SL up to section B, questions 1 and 2[/size][/font][/color]
Last reply by balloon, -
- 19 replies
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I haven't seen a thread about organic chemistry yet, so I'm starting one since I kind of need help. I would like to know certain things: 1) Does non-cyclical geometric isomerism occur only in alkenes? 2)It says in the study guide that some of the characteristics of geometric isomers are: - In the cis- isomer, H-bonds could form within the molecule it self. - in the trans- isomer, H-bond occurs between molecules. What I dont understand: wouldnt H-bonds form only when you have an OH group on the attached R-groups? So, how would that characteristic be valid for all cis and trans isomers? 2) I always don't quite understand elimination reactions. I know the mechanism an…
Last reply by Tilia, -
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I am self-studying option B, Human Biochemistry. I have found it ok so far as it overlaps a lot with HL Biology. However, I'm getting stuck in certain things on the syllabus that the books I have dont explain properly or unclear. So I have a few questions, that I think those of you who have done it with your teacher may be able to answer. B.6.2: Compare the structures of cholesterol and the sex hormones: It says stress on the steroid backbone and the difference in functional group. That's all the books mention as well. Seeing that its objective 3, I dont have enough details and I dont really see any other difference. B.7.2: Compare inorganic catalysts and biological …
Last reply by ozolins, -
- 3 replies
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Hi we just did an experiment on the topc: tests for anions and cations, we just basically had to follow the instructions e.g. "put about a 1cm depth of the solution in a test tube and add an equal volume of dilute nitric acid. now add a few drops of aqueous barium chlride or barium nitrate." then observe the changes and record it. It was a qualitative experiment as what my teacher says and after the first step we had to identify the ions e.g. carbonate ions, sulfate ions etc. based on the observations we made. We are supposed to do an IA on this and i have no idea how to start it nor what to do. i am trying my best to search any information concerning anions and cat…
Last reply by herong2x, -
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I've been having great difficulties with chemistry revision, and I was wondering if anyone had chemistry notes to share? Or even any tips that could help
Last reply by Joey, -
- 6 replies
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I am taking SL Biology and I find the study guide extremely useful. However, I have Chemistry at HL. I was wondering if I should buy the Chemistry Course Companion or the study guide ? I understand the subject quite well, as in, what is taught in class. All I need is a book which covers all the IB assessment statements (kind of like the Biology Study Guide)... but I'm unsure as to whether the Chemistry Study Guide is good enough for that? For all those who used the Course Companion, is it good?
Last reply by JourneyTo, -
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Ok. So for my lab i used a given quantity of iron to react with excess copper(II) sulfate,which produces COPPER AND IRON SULFATE. For this lab, we are supposed to determine the percentage yield of copper and i got slightly over the theoretical yield Theoretical: 1.7g Cu Actual : 1.72g Cu How is this possible, i mean it isn't possible to produce more than the amount of reactants. It would make sense if the actual yield was less than the theoretical yield............. So i really need an explanation for this. And for this lab, what kind of things would be considered as limitations&errors??? (…
Last reply by Hedron123, -
- 31 replies
- 28.9k views
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Last reply by narathiel, -
- 15 replies
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I kind of need help on finding the uncertainties for the measuring cylinder and such..and dropping pipettes. I'm doing my biology practicals and desperatly need them. Anyone has an idea? I need them soon if anyone's willing. Thanks alot.
Last reply by IBdoc, -
- 6 replies
- 704 views
Alright, so, I graphed some data from an experiment and the points resembled a rational relationship between the variables, i.e., a curve fit would produce a curve resembling a rational curve. I needed to find a line of best fit in order to calculate the gradient so I changed one axis to "1/x" when originally it was just "x". This produced what I needed; the data now lined up linearly and the program fit a linear fit perfectly. My problem is, I need to include error bars on my graph, but I am unsure of how the uncertainty would be converted when I did this with my graph.. Any help would be greatly appreciated!
Last reply by kristers, -
- 2 replies
- 857 views
Hey guys! i need your help! I have to do a thing called 'desing' :| i have to make a project of lab... ;| I have no ideas, what can i do.. i mean i can not figure out the topic ;/ please, help me just with making a good and easy topic! Time is running out, please help! The task is ; [b]Design an experiment which requires the use of the gas laws[/b] [b]coefficients are determined, temperature or pressure dependence on volume [/b] i m waiting for ideas! I hate chemistry.
Last reply by Tilia,
