Chemistry
For Chemistry Discussions
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Hi everyone! I'm taking chem HL in IB, but I've always had a hard time with the equations involved. :/ The fact that I don't understand these has been penalizing me on my tests by almost 15 points every time. Is there a good website out there that can help me, maybe by going through a few examples? Thanks so much for your help!
Last reply by theboro76, -
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Could someone please help me out with the above lab report. It is a design lab, so could anyone tell me how to go about the procedure and the hypothesis. Readings would be of great help, this is only for class homework.
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Hi there, So I'm having trouble getting started with my Design Lab. My research question is: - How will the density of straight chain carboxylic acids depend on the chain length? Any suggestions how I can get started...I'm not even sure what I'm actually investigating - what experiment. See, our teacher helped us pick research questions and there wasn't much choice...I just said yes to this one, hoping after researching I would find out what I'm suppose to do..but that wasn't the case. Any help at all is appreciated. P.S - I have Chemistry SL
Last reply by Pringels, -
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is determining whether electrical conductivity of a solution is affected by the concentration of a salt a good chemistry ia topic? if not please give me examples to improve this... it has to be related to the conductivity of salts
Last reply by khimberleigh, -
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Read the other comment for my question... Actually, I have an idea. Would there be a possibility to measure pH of a series of, say, alcohols? Or should I find something else?
Last reply by CJSelf, -
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So I've done my first draft of a design for this internal assessment, my teacher said I did everything in a correct way except my method wasn't correct. I have to use a titration to show how heat or concentration affects the stability of iron 2+ tablets. What I don't understand is how does a titration show the stability of an element (assuming stability is how full an outer shell does it have)? Do I increase the concentration of potassium permanganete and see if the volume needed for the end point is lower? I just don't understand... Please help!!!
Last reply by berkay560, -
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Does anyone have a good idea for a Chemistry SL lab? It's topic is bonding. Thanks!!
Last reply by Sandwich, -
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Hi! I need some help with a design lab. My plan this far is to make a report concerning the viscosity of liquids and thought of working with homologous series. The research question looks like this so far: "How does the length of a carbon chain affect the viscosity across a homologous series?" So my question is; is this too easy? If so, do you have any suggestions what I could do instead? I really want to make this a good one. I have Chemistry SL.
Last reply by GeneralIdea, -
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Hi! Iron(ll) is oxidized to iron(lll) to manganate(Vll) in acidic solution. Below are the two balanced half-equations: MnO4- + 8H+ + 5e --> Mn2+ + 4H2O Fe2+ --> Fe3+ + e a) Write the total balanced equation for the reaction of Fe2+ with acidified MnO4-(this is a redox reaciton; balance the number of electrons exchanged b) 1.324g piece of wire containing Fe was reacted with a large excess of dilute H2SO4 producing a solution of Fe2+. The solution was made up to 250 cm3 and a 25cm3 portion was titrated against 0.0200mol/dm3 KMnO4, requiring 23.05 cm3. Calculate a percentage of iron in the wire , I managed to do a) , however b is impossible for me, it would be kind o…
Last reply by Drake Glau, -
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In this experiment I am supposed to count the concetration of vitamin C in tested sample. Vitamin C (ascorbic acid) has the formula C6H8O6, and can be oxidized to dehydroascorbic acid C6H6O6, using iodine. Oxidizer comes from potassium iodate and potassium iodide, which react with each other in presence of hydrochloric acid. KIO3 + 5KI +6HCl → 3I2 + 3H2O + 6KCl Iodine reacts with ascorbic acid as shown below: C6H8O6 + I2 → 2HI + C6H6O6 Due to this reaction, formed iodine is immediately reduced to iodide as long there is any ascorbic acid present. When ascorbic acid has ran out, the remaining iodine reacts with starch indicator. In order to make that reaction happen,…
Last reply by Rigel, -
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I want to dilute a solution of a metal salt by 10 fold dilution so like 10 metal salt 90 water but i want to use 40cm^3 of that is it still 10 fold each time?
Last reply by Drake Glau, -
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I'm doing an ib specific lab, if I did external research for my lab, should I use footnotes and biblio? or just biblio? and what format should I put it in? Thanks (:
Last reply by Drake Glau, -
Lab Report Equilibrium and Catalysts
by Guest Humaira- 5 replies
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I have to do a Design IA on the effects of catalyst on equilibrium, I know that catalysts only reduces the energy needed for the reaction and speeds up the attainment of the equilibirum state so products are formed more quickly. The problem I am having is figuring out a chemical reaction with a catalyst to use. As well as the method to carry out such a reaction(ie when do you add the catalyst? when making the solution for the forward reaction? and after the soluton is made for the backwards reaction? ) the chemical reaction I have thought of so far is: Cr2O72-(aq) + H2O(ℓ)--->2 CrO42-(aq) + 2 H+(aq) thanks in advance!
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This is the task I was given. I currently will need to think about what to do for the lab experiment. I do not know exactly what I have to do. I am suppose to investigate the homologous series and I want to find out a way to do this. If anyone is familiar with this topic (more than I am) please share with me some procedures for me to conduct this lab experiment. The task... Open ended experiment Method: Individual work . Report should be submitted individually. Duration: 2 weeks You are to plan, design and conduct an experiment using suitable apparatus for ONE of the titles below: 1- Investigate a method of producing alcohol in the lab and how you could determine that you…
Last reply by larrut, -
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This is actually for a geo IA, but I have to analyze the properties of soil, so I guess it fits. For my geo IA, I want to answer the question "How is the quality of soil affected by the presence of major transportation routes in [my town], and what might this tell us about the town's sustainability?" The problem is that, although my teacher recommended this topic to me, everyone I talked to says it's illegal to stop at the side of a road, and collect soil samples. Is it really? Because if my teacher said I should do it, it shouldn't be THAT unethical.
Last reply by dniviE, -
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Hello I'm in IB1 and I have want make my standard level chemistry higher. I already have 3 high levels (physics, math, english B) but I don't think universities in the us/uk value this subject very much and I thought I'd take chemistry HL to compensate for that. My 1st term score was 38/42 and I want to raise it or at least keep it the same. Is that possible if I take HL chemistry?
Last reply by AkirpapAnalif, -
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I did a past paper 3 the other day for HL on spectroscopy and there was a question about how would the splitting of d orbitals when nickel had formed ligands change the colour of the solution if it were nickel and ammonia or something like that but the question was basically askng you to predict the colour. How do you predict the colour? There's hardly anything about it on the course. I had it explained to me by this chemistry god guy who goes to oxford and did the IB. Anyway I get the whole sigma donating and pi acceptng properties stuff but he said he cant explain it more without going into group theory which is undergraduate level. Anyway how much of this do we have t…
Last reply by I.B.a.zombie, -
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Hey, We've done chapters 1,2,3 and 4 (along with the AHL bits) from the syllabus. We did the equation E=hf during chapter 2, but I can't find it anywhere in the syllabus, even for the AHL part. However, it is there in the textbook, though there aren't any calculations. I was just wondering if this is there in the sullabus and if i've managed to miss on it somehow
Last reply by ananya.agrawal95, -
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The following link will take you to my Skydrive account where I have uploaded a Powerpoint with IB chemistry notes by topic header. Some subjects are incomplete but its still a valuable resource. http://sdrv.ms/T3TKGs Enjoy guys Unfortunately I had trouble uploading it because I couldn't locate it on my laptop so this was easier.
Last reply by ananya.agrawal95, -
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Hai guys I need some help to think of an Ia to do with electrolysis or electroplating and only those two options (topic 9&) please any ideas by today
Last reply by Gaby, -
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I don't know if it's like this at other schools, but at my school, in the first year of IB chemistry you do chapters 1-6 and 11 of SL and HL material combined, and then in year 2 you do chapters 7-10 (SL/HL combined) and the two options. (We use the Pearson Baccalaureate HL book) What do you think are the hardest topics in SL or HL chemistry? We're on the periodicity chapter right now -___- it's not exactly "hard", just so much to remember.... but I love chemistry
Last reply by Lero, -
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I am doing a chemistry IA where I investigated the enthalpy change of displacement reactions (e.g. zinc powder and copper sulphate). The reaction occurred in a polystyrene cup with a lid. A hole was created for the thermometer to pass through and contact with the solution. I realized that some of the heat generated by the reaction is lost to surroundings with this setup. Is there any way that can minimize heat loss? I found something called "bomb calorimeter". It seems to be able to preserve heat very well but is it only used in combustion reactions? I am working on the evaluation part. Any suggestions?
Last reply by Bernardo Silva, -
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Hi Guys, I really need you help, I have to give in a lab report day after tomorrow. It is about the rate of reaction and the factors which affect the reaction. I did it at the beginning of the year and can't remember a thing from it. All I have are results, which are HCL concentrations over time, Does anyone have any idea how this could have been carried out? Thanks for your help in advance.
Last reply by Zostale, -
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Hey guys, I'm supposed to be doing a DCP, CE lab report for tomorrow. Our teacher gave it to the class today, unfortunately for me I wasn't in school so I didn't get the sheets. But one of my friends e-mailed me the results of the experiment we're supposed to be evaluating. Now none of them are online to ask so...I'm not too sure what the equations were, so I can't really do it properly. And I know regardless of whether I was there or not I know he'll want it handed in. I've attached the results here so anyone who's better than me in Chemistry can use their intelligence to try and work out what experiments could cause these results. Thanks so much. My intuition along wit…
Last reply by Zostale, -
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I have a couple of questions about errors in measurements. When we are to calculate the percentage error, how many significant figures does the error has to have? For example, when we want to calculate the percentage error of 5.1 +- 0.2 g, is it 4% or 3.9%? What if it was 5.25 +- 0.25 g, would it be 4.8% or 5%, I'm confused... And what if we were to calculate the sum of two such quantities: 25.0 +- 0.5 g and 15.0 +- 0.5 g? What is the result, 40 or 40.0, and what is the error, 1.0 or just 1? Last thing, cause I've seen more than one version: when we need to know an uncertainty of, say, volumetric cylinder which has a line very 1 cm^3, is the uncertainty of it +- 1 or 0.5…
Last reply by akrasuski1, -
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HOW DO I FIND IT AND WHAT IS IT AND Ojeolkheriogh!!!!! portfolio due tomorrow.
Last reply by MLI, -
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I'm testing the effect of temperature on the voltage of voltaic labs. I've heard from past students that temperature is the worst variable to control. The last lab that I tested temperature, I scored a 2 so I'm not sure if its a good variable to test. Any advice on testing this variable????
Last reply by Gee, -
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Hello. I am a Pre-IB student and for some reason there is always something wrong with all my chemistry lab reports. I've done two labs and whenever I get the labs back there's always something wrong with it. After the first lab I looked over the report and tried to do better in the next one but if came out worse than the first. Could someone please offer some tips to making a good IB lab report?
Last reply by ChocolateDrop, -
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Hi Everyone I am doing an experiment in which i have to investigate the solubility of group 2 hydroxides(Sr, Ca, Ba, Mg) with Hydrochloric acid. My main issue here is that Firstly, some of my values are incredibly off compared to the literature value. For example, for Mg my value is 1.77g/dm3, and the literature value is 0.0012g/dm3. This is really different. But i cannot think of anything that i did wrong Secondly, what are the controlled variables in this experiment? I am able to think of many because now my HCl concentration is changing as per the different Metal Hydroxide. Thanks loads!! i need it really bad!
Last reply by JennaGonzalez12, -
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I'm starting dp next year in Jan, so I thought that maybe if I start to chemistry a bit earlier it would be useful (everyone's been saying that it's legit hard). I even bought the Chemistry Course companion but I dont know how to go about with it. I'm finding it quite difficult even though Chemistry is one of my favourite subjects. Any tips or suggestions?
Last reply by aangel, -
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Hi guys! I writing a report for my internal assessment, in which I investigated the effect of the concentration of the electrolyte at the anode of a voltaic cell on the total potential difference across the cell, and I have stumped upon a problem with formulating the aim. The thing is, that there is an equation for the relationship which I am investigating (the Nernst equation) and I do not know whether my aim should be to just "investigate the relationship" or to "investigate the relationship and see, whether it follows the Nernst equation"? This is important because there are several sections which I will have to write differently depending on the aim.
Last reply by Drake Glau, -
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Hi guys! I'm doing my report on voltaic cells and I wanted to know what the ion solutions at each half-cells are called. I've heard that they are called electrolytes, but I am hesitant in believing this since the liquid in an electrolytic cell is also called an electrolyte. So what is your opinion?
Last reply by norsul, -
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I like chem as a class, but my labs are far from great.. I can't do uncertainties... but I want a 7 so bad, and I'll do whatever it takes My teacher said that at my current level I'm in the 5-6 range.. Any tips on how to get better labs?
Last reply by norsul, -
Hi guys! I'm currently writing one of my lab reports and this is my first one which includes the design part (well, I had one before this one but it failed completely, so this is basically the first one) so I want things to be done well! Until now I've been under the impression that the method should ALWAYS be described in narrative form, i.e. "First this was done, then this was done because of that and then this was followed by blah blah blah...". But recently I've found some sort of a checklist (link at the end of the post) for the chemistry IA and it stated that you can actually describe the method in the form of bullet points / numbered steps. This checklist is not so…
Last reply by norsul, -
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Hello! We are supposed to come up with an experiment where we will be investigating a trend within a function group, preferably alcohols since we have got more than five different alcohols available. (Five is the magic number.) However, the only topics I can come up with are very complicated. For instance I had an idea of measuring the initial rate of reaction with a fixed acid by varying alcohols. and see of the intial rate of reaction would vary depending on the alcohols. This would not be an easy experiment since the product, an ester, would make its own layer, and it would therefore be hard to measure the pH of the remaining reactants accurately. So, do you have any …
Last reply by IB-Adam, -
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Hi, We're doing a lab with wavelengths, spectroscopes and different elements. In order to do calculations for error though, we need to know the uncertainty for the spectroscope! If anybody knows it, it would be greatly appreciated if you would share Thanks
Last reply by SerUmbras, -
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I am struggling with determining the percentage composition of calcium carbonate in 2.764g of limestone sample. I used the method of back titration: I first added 60ml of 1M HCl to a beaker with the 2.764g limestone. All the contents in this beaker were filtered, such that only the calcium chloride and the excess HCl were collected in another beaker. This mixture (excess HCl and calcium chloride) was then diluted with distilled water to 500ml in a volumetric flask. After that, 25ml of this mixture required 20.9ml of 0.1M NaOH for complete neutralisation (reaching end point) The question here is: Determine the percentage composition of CaCO3 in the 2.764g of limestone sam…
Last reply by -John Yeah-, -
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Hi, I'm in a hard situation and I need advice. I took Chemistry HL before I found out that my IB chemistry teacher couldn't speak English at all. She speaks Estonian, which I don't understand. All my subject choices have been confirmed and I can't change anything anymore. Should I self study Chemistry instead of wasting my time sitting in class and not understanding anything? I don't know if it's a good idea as it seems quite risky.
Last reply by Shenrongrong, -
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What is a good option for Chemistry? My school teachers us, Option B: Human biochemistry and Option Medicine and Drugs. I really like Option B and find it incredibly easy (only had about 2months learning it). BUT I absolutely hate Med&Drugs and just can't seem to get a hold of the information (been studying since late 2011). My exams are this November, and I'd really like to learn another option preferably an easy one in addition to the (B & D) just in case. ANY suggestions?
Last reply by IB Failing, -
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Our teacher makes us define ionization energy as 'the energy required to remove one mole of electrons from one mole of atoms or ions of the same element in a gaseous state.' She got this from the damji book. However, most sites/books define it simply as the energy required to remove an electron from the valence shell of an atom/ion in the gaseous state. Which one is right?
Last reply by ananya.agrawal95, -
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I have 2 tasks to do, if anyone helps me, I'll be really grateful. 1. Iron (IV) sulfide (disulfide iron) was subjected to oxidation reaction. It brings 2 x 10^5 m^3 of sulfur dioxide. The yield of reaction was 89.2 %. Calculate the mass of iron (IV) sulfide. This is the oxidation reaction (it is already squared) 4 FeS2 + 11 O2 = 2 Fe2O3 + 8 SO2 2. What is the yield of complex process, which holds in two stages? Yields of the following stages are given below: S + O2 = SO2 yield= 95 % 2SO2 + O2 = 2SO3 yield = 70 %
Last reply by abhinavbhasin, -
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how many IA we are supposed to write ? thanks
Last reply by carpediem, -
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I just need a general idea of how to process the data. We're using a solution of potassium...iodate (? i'll have to check later), a starch indicator, and water against nitric acid (0.030 mol dm^-3) and it's two different testing conditions. For the rate, do I divide the molarity or the volume or what by the time it took for the color to change? The teacher didn't really explain anything. Other than that, I should be fine for this. Thanks for the help in advance!
Last reply by Argy, -
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We've gotten our math IA questions (and deadline) but nothing about chemistry, or biology for that matter.. When are we supposed to hand them in?
Last reply by Sammie Backman, -
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Okay, so I get the theory behind this lab, but the uncertainties are killing me. So, we had to measure the time it took for the iodine clock reaction to work. Then we have to get a straight line graph by plotting ln(time) and 1/Temperature. So the slope is Ea/R. But how do i determine the uncertainties on the 1/Temperature and ln(time) ? so for example if my temperature is 208 +/- 0.1 and time is 23s +/- 0.5s? how can i know what the uncertainty on 1/Temperature and ln(time) is? Any ideas will be much appreciated! Thanks!
Last reply by NZIB student, -
Hi guys. I'm thinking about a design lab and came across this thing: http://www.compacitypro.nl/Portals/3/D_CORROSIO_T_EN.pdf I understand most of it, but under 'Measurement' I don't understand how the Fe3+ ion concentration is measured? 'After 20-40-60 minutes, investigate the increase in the iron ion (Fe2++ Fe3+) content of the corrosive medium.' Any help would be very much appreciated!
Last reply by Fish, -
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Last reply by The Economist, -
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Please sombody help me! My teacher doesnt explain anything and he gave us an IA of a topic we havent covered. I just want the basics of a simple and good SL lab. Please pretty please!
Last reply by droemers, -
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- 651 views
Does anyone know if there is an IB Chemistry tutor anywhere in London?
Last reply by Lostjak, -
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Hello fellows! I need some help with uncertainty. If the empty crucible weight 27,63g and the crucible with a compound weight 30,72g. What is the uncertainty for the both of them? How do I calculate it , please explain. Thanks for respond!
Last reply by IB Failing,