Chemistry
For Chemistry Discussions
1,617 topics in this forum
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Hello, I am beginning to work on the internal assessment in my Chemistry class. My research question is: How does the affects of pH vary with the vitamin C concentration in white apple juice? I also wanted to discuss that I will be doing titrations to determine the content of the vitamin C content. I plant to titrate with potassium iodide. I wanted to ask what I would be using the starch and vitamin C tablets for. Apparently, I needed both of these materials with my lab. My independent variable is the pH values found in the white apple juice, and this will be manipulated by using buffer solutions. The buffer solutions can help me isolate the environment, so I can determin…
Last reply by KingCobra183, -
Please help! I need a database topic for my chemistry IA and i want to investigate hydrocarbons and boiling point. But I have NO IDEA what my research question can be? Any suggestions on a research question and how to do it, please? thank you so much!
Last reply by Gaby, -
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Hello! So I've been faced with a dilemma on my IA and I've spent a good amount of time trying to figure it out but I can't seem to do it. So my IA is on buffering capacity but I can't really find any examples on how to calculate for buffering capacity. I know there are equations out there but every time I visit new websites, new equations pop up on how to calculate for buffering capacity and it just confused me even more. If someone could point me in the right direction of how to calculate the buffering capacity of a solution when you have the moles of the strong acid being added and it changes by 1 pH (not sure if I need anything else), that would be really helpful. …
Last reply by Sandy, -
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Okay, so I've been busy with a lot of things lately. I had my HI finished just a few days ago because a bunch of things had gotten in the way in January granting me an extension, I've been travelling a lot for debate, and to make a long story short my chem IA has been on the backburner for a liiiiittle too long. My original experiment was one that involved the cooling ability that different molarities of salt water could have on a closed system, to see if an in-ceiling air conditioning system powered by naturally cooled sea water could be feasible. It was a really neat topic but I have absolutely no time to build the apparatus I had designed for it, so I'm stuck between a…
Last reply by Sandy, -
Chemistry HL
by klem- 0 replies
- 466 views
Hi everyone I have to choose IB subjects in a week and I am thinking of choosing Chemistry HL. I am comfortable with math but not super-good. Would chem HL be too hard? I am not doing any other sciences or anything like that, but I want a balanced diploma with humanities and sciences. Therefore, I am taking chem hl. Is it possible with a good score?
Last reply by klem, -
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my IA was on the effect of temperature on ascorbic acid/vitamin C and I'm trying to find the molarity of vitamin C in each trial. I used 20 mL of orange juice (which contains all of the vitamin c), 150 mL of water, and 1 mL of indicator. on top of that I titrated in an iodine solution whose volume varied depending on the trial. I have the # of moles of vitamin C in each trial, but for the liters of solution in the molarity calculation, would I use the 20mL orange juice, or OJ+water, or OJ+water+iodine solution? hope this makes sense!!
Last reply by kw0573, -
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So I'm in year 1 and I'm having a lot of trouble finding an idea for my IA. My teacher says that the format of the idea has to be "Effect of ______ on ______" but I can't find any ideas to match that, so does anyone have any suggestions?
Last reply by Gaby, -
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Just wondering if the synthesis of anything is an IA or a regular lab activity.
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Chem IA not good enough?!
by Guest- 3 replies
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Hei. My chemistry teacher hasn't approved of any of my proposals for my IA, and now I'm falling behind. The one that really caught my eye was the "effect of HCl on medicinal tablets, specifically Tylenol". However, he explained to me that there isn't really a result for this except that pH decreases. I understand his reasoning. I need a way to refine this. I've no clue how. I thought of reaction rate, but this topic was solely based on what happens in the stomach. There is gastric acid or HCl in the stomach that digest whatever enter the stomach. I can't react NaOH with HCl to determine the effect on the tablet. I understand that that's a titration lab, but I'm not …
Last reply by kw0573, -
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Our class got printouts of questions from the Cambridge book but no answers...can anyone link me to them so I can check my answers?
Last reply by NiCKEL, -
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Hey guys so it's time to calculate uncertainties for the IA which is due in two days. My teacher has told us that there is new uncertainties calculations for the new 2016 syllabus, although I searched videos/syllabus/forum posts and could not find any evidence of this. So what she said was: Old syllabus: For adding or subtracting A and B, you add or subtract uncertainties of A and B. Multiplying or dividing, you calculate percent uncertainties. New syllabus (what we should be doing): Adding and subtracting A and B: Square uncertainties of A, square uncertainties of B, add them together, and square root the whole thing. Multiplying and dividing A and B: Take the stand…
Last reply by Elite X-Naut, -
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I don't understand anything my teacher is saying, I get 5s in all my exams. Its 5 months into the course and I reaallllyyy don't know what to do everyone in my class is extremely smart and I can't understand what they explain. All I do is cram the night before exams and watch videos on the topic. I can't wrap my head around the trends and calculations. What do I do?
Last reply by kw0573, -
- 2 replies
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Do you have a Dr. Geoffrey Neuss Multiple choice qustion test (SL) from topic 4. I have a test and it would help me to see where I stand.
Last reply by Msj Chem, -
Chem IA: Research Question
by Guest- 1 reply
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Hei. So, I'm really interested in the hydrogen spectrum,and wanted to experiment with it for my Chem IA. I wanted to determine the wavelengths of Neon, Helium,a nd Hydrogen, however, I'm having trouble forming a research question. Help please?
Last reply by King112, -
References
by maina- 1 reply
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Hi Does anyone know how many references to scientific sources should we have in evaluation in IA? My Biology teacher insists that 5 is a bare minimum but I was wondering whether it is the same in Chemistry? My Chemistry teacher is new to the IB and is not very helpful..
Last reply by Elite X-Naut, -
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I have the IB Chemistry questionbank and I've done in-book questions but where can I practice organics beyond those? Since the 2016 curriculum has a lot of differences with 2009 the questionbank doesn't help much, and I can't find any 2013+ past exams. Where is a good place to go for practice
Last reply by kw0573, -
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Hey! I've taken chemistry HL and my IA is about studying the effect the change in concentration of different electrolytes at cathode has on the emf of a voltaic cell. I've kept the electrode and electrolyte at anode constant and observed the change in emf for different concentration of (8 different) electrolyte and electrode combination at the cathode. The problem I'm facing is in the introduction. Can you give an example for purpose of this IA? Basically, why it is necessary to know the change in emf for different electrodes.
Last reply by Siddhakshi, -
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I'm graduating June '17 and I was wondering how much the course had changed from 2014 onwards? I want to buy the IB oxford chem guide that was published in 2014 but i am not sure if the course has changed too much for that to be useless?
Last reply by NiCKEL, -
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Hei. I need desperate help with this Redox Titration lab calculations. I suck at chemistry, I go for extra help and read text book and only understand for one day, and then I'm confused the next. Anyways, we had to experimentally determine the % H2O2 by mass in a solution given: MnO4 + H2O2 + H -> Mn + O2 + H2O (charges are given). Procedure: Combine (in order) 25 drops of H2O2 solution, 20.0 mL of deionozed water, and 20.0mL of 1.00 M +/- 0.05 M H2SO4 in an Erlenmeyer flask. Titrate with 0.0400 +/- 0.0005 M KMnO4 until solution decolorizes to a persistent pink. Raw Data: Mass of Erlenmeyer flask: 115.711 g Drops of H2O2 solution: 25 Mass of Erlenmeyer fla…
Last reply by kw0573, -
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Hei guys. So today, my chem teacher announced that we need to pass in 3 IA proposals by Friday. I'm so stumped. I suck at chemistry. Its interesting, but so complex for my wee-little brain. I need ideas or at least a guide. I don't want anything too difficult (obviously). I did pretty good on the Acid & Bases unit, and also RedOx unit. Others were pretty sucky. Or, do you know any websites that may have a list of topics? Thanks!
Last reply by Sandy, -
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I have read a lot that Vitamin C is very soluble in water. But how is that possible if it is a weak acid? Shouldn't it only partially dissociate in water? The thing is, I carried out a titration to determine concentration of Vitamin C. Theoretical value was 0.06 moldm^-3 while my experimental was 0.05. Could an error be that ascorbic acid does not fully dissociate into water?
Last reply by kw0573, -
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So I have come up (with the help of my teacher) with an interesting idea for an IA, and I would like a second opinion to make sure it fits within the fields of what qualifies a topic as chemistry I guess. The idea was to look at violin strings, comparing cheap ones from quality ones, and seeing if maybe electroplating a cheap string would improve the quality, saving money possibly. Thoughts?
Last reply by kw0573, -
- 5 replies
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Hei. So I'm have trouble calculating the % yield for NH3 of: N2 + 3H2 = 2NH3 I know that you're supposed to find the limiting reagent, which is N2, and I know for sure that I got that right. The masses given for each molecule is 400 kg (N2), 200kg (2H2), and 220kg (2NH3). I know that you're supposed to do the (molar mass of NH3)/(220)) x 100, but I'm not getting the right answer. What am I doing wrong? The correct answer is 45.2%
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My chem IA is coming up, and I need an SL idea by tomorrow, with quantitative data that I am able to measure. If anybody has any ideas, it would be greatly appreciated. Thank you so much, whoever answers. The idea of removing tarnish from silver was already rejected, mainly because it has no quantitative data.
Last reply by ShootingStar16, -
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Hi my chemistry IA is due tomorrow morning (around 10ish hours) My IA is related to Activation energy and Arrhenius' Equation: lnk = -(Ea/RT) +lnA So in this richard thornley video about the Ea of glow sticks:https://youtu.be/b41fRjI6kuQ?t=1m28s he sets the y-axis as the natural log of illumination, can someone explain how or why he is able to do this? and why this works out? because I just can't seem to be able to identify the link as to why ln k is the same as ln of illumination! Thanks
Last reply by Abubla, -
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Hello everyone, I'm working on a chem IA related to voltaic cells, and my instructor told me to refrain from Group 1 and 2 metals, but from what I think I know, magnesium doesn't seem too bad in a voltaic cell set up, right?
Last reply by Sandy, -
- 6 replies
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7.1 (Equilibrium) Application: determination of the relationship between different equilibrium constants (Kc) for the same reaction at the same temperature. I do not quite get this learning objective. I thought there is only one equilibrium constant (Kc) for the same reaction at the same temperature? What does it mean by relationship between "different equilibrium constants"? What does it want me to know?
Last reply by Msj Chem, -
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So, thing is, the complexity of an experiment and the ingenuity required to devise it come under the criteria section of "personal engagement" since other section evaluate you based on how well you performed within the context of the investigation. For this reason i decided that my IA topic would simply be an exploration of the boiling points of straight chain alcohols related to their molar mass. "Personal engagement" only accounts for 2 of the 24 available points, but I'm worried that the simplistic premise will result in dropped points in other areas. Any insights?
Last reply by Sandy, -
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Hello people! The other day I went to see my teacher and ask her about my Chemistry IA. I wanted to do something like an experiment to determine the rate of reaction of something. However, she told me to try find something that is computer-based like a stimulation. That got me thinking quite a bit. The question is: Has anyone got good grades for computer-based experiments? If so what did you do about? Which is better (computer-based or experiment-based)? Thanks in advance!
Last reply by Sandy, -
- 3 replies
- 404 views
If I want to react iron nails and different concentrations of acid, should I choose 1 nail for a certain concentration and keep the nail throughout 3 trials or should I switch every single time? The nails are already used to start with; so switching nails has the disadvantage of not knowing what it previously reacted with, but using the same nail means it will constantly get worn down, so will that affect rate of reaction? Which one's the best, I need to make the best out of the situation.
Last reply by IB_taking_over, -
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I know this isn't really part of the curriculum but where does the oxygen come from when an aldehyde turns into a carboxylic acid in the oxidation of a primary alcohol?
Last reply by NiCKEL, -
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Hello guys- can someone please educate me on the teacher's responsibility with our IA's? Is he or she responsible of guiding us away from a research question that is setting us from failure or is the guidance never provided with the IA's. Thanks
Last reply by guanemo, -
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Do electro(nucleo)philes refer to just the atom or the whole molecule? I hear the three types of nucleophiles are lone pairs, sigma bonds, and pi bonds. Would an electrophile be like the H+ ion in HBr then, or just HBr? Is it wrong to call the long-pair-containing molecule the nucleophile?
Last reply by kw0573, -
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So I'm getting ready for a difficult organic test and one of the few things I still don't understand is how one can predict the products of a free radical equation, such as: Cl* + CH4 = CH3* +HCl More specifically: How did the Methyl group become radical, and how did Cl drop its radical?? What method do i use to predict products in a free radical equation?? Please help
Last reply by Msj Chem, -
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Does anyone have any vague ideas for a chemistry SL IA having to do with the environment, animal ethics, etc. or can just talk through some ideas to narrow it down? Thanks!
Last reply by Bobby K., -
CHEM HL IA
by BMH- 3 replies
- 8.7k views
hello guys so basically all my classmates have their experiments done already and are starting with their lab reports and then there is me. I am literally freaking out. I was originally doing my experiment on effect on NaCO3 on the foaming capacity pf soap, but i felt like it was too simple to be an IA. I have presented my teacher with many ideas but he would always come up with something wrong about it. My previous chemistry teacher advised me to do something on enthalpies but i dont know how to relate it to a personal engagement. Can anyone please suggest some strong HL topics im very desperate.
Last reply by Sandy, -
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​Hello, ​I am doing SL Chemistry and I really would like to do my IA on water quality. By this I am thinking of measuring the nitrate ion concentration or the amount of pesticide on the quality of water to see if more of the ions would make the water more polluted or not. With that said though, I am having a hard time coming up with what the dependant variable should be and now I am thinking if I should do something else for my IA instead, since it may be difficult to measure. Would doing a IA on water pollution be realistic or should I just do something else? Any help would be much appreciated! Thanks in regards
Last reply by Guziec, -
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I'm reacting various concentrations of acid with Fe (s) and titrating the solution with potassium permanganate. since there is already acid in the reaction, do I have to add further acid to the aliquot before titrating? Does it matter if the [acid] is different?
Last reply by NiCKEL, -
Kinetics/Equilibrium
by Guest- 6 replies
- 516 views
Please help me understand this question!
Last reply by Vioh, -
ThermoChem
by Guest- 1 reply
- 385 views
In the following reaction, what is equal to the rate of production of NO gas? 4NH3 + 5O2 -> 4NO + 6H2O The answer is "four-fifths the rate of disappearance of O2 gas. I don't understand why, please help!
Last reply by Msj Chem, -
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I have written my chemistry IA on voltaic cells, but while re-reading my IA I realized that the Personal Engagement section is not evident. I would really appreciate it if someone could help me with this.
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Equilibirum
by Guest- 4 replies
- 448 views
Please help me understand why the answer is D.
Last reply by kw0573, -
I need help with SL ThermoChem
by Guest- 1 reply
- 1.5k views
1) 870 J of heat is required to vaporize 4.5 g liquid bromine (Br2). Whta is the molar heat of vaporization of Br2 in kJ/mol? The answer is 31. 2) The evaporation of 1.00g of ethanol is accompanied by an enthalpy change of 879 J. What the enthalpy for the following change in state? CH3CH2OH (g) -> CH3CH2OH (l)
Last reply by Vioh, -
ThermoChem
by Guest- 1 reply
- 448 views
The molar heat of vaporization of water is 40.7 kJ/mol. What is the energy change in 2.0 g water that condenses at 100C? I'd like to know why the answer is exothermic?
Last reply by Vioh, -
Chemistry SL
by Guest beyondtheimagine- 11 replies
- 1.1k views
Hello! I was wondering if someone could help me out here... I'm currently doing chemistry sl and my IB exam is in May. I'm wondering if anyone could recommend me any textbooks or resources that can help me learn the material? My teacher tends to skip over some lessons and the notes I currently have..doesn't really help me understand the topics very well... Thank you! Chantel
Last reply by tiff6788, -
- 3 replies
- 433 views
The only thing preventing my IA from getting approved is that the acid used in a procedure is too concentrated so my teacher doesn't want that to be used...what effect will simply using a more dilute solution have on the procedure? It is a thiosulfate titration.
Last reply by kw0573, -
- 3 replies
- 5.5k views
Hi Fellow!!!!! I am doing Chem HL and we are asked to produced an outline of our proposed Chem IA by early Feb and I'm really lost + my chem teacher is out of reach due to the holidays. I have had some ideas going through my mind, but I'm not sure if they would work for HL cuz they seem to be rather straight forward and simple. I really hope you guys can give me some advice and idea on this These are what I've though of so far: 1. What are the impacts of temperature on the preservation of Vitamin C in selected vegetable/fruit (TBC). My concern with this is that, will i have enough things to write about it? I've done some researches on this, the experiment itself…
Last reply by Thrashmaster, -
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Solved. Thread closed by poster.
Last reply by JiGGie, -
- 1 reply
- 922 views
Hello everyone! I am doing an IA on the effect of different weak acids and their buffering capacities, and I am at my introduction. I would like some help with separating what the introduction is and how it differs from the background. Also what can I include in my research question to make it more focused?
Last reply by happymelons, -
- 2 replies
- 1k views
Hey, I need help about periodicity. What are the common questions about this topic? What is the most important to know about this topic? I have test soon, so please help Thank you.
Last reply by tiff6788,
