Chemistry
For Chemistry Discussions
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Hey people, I've been away for a while. The good thing is that I'm back and I'm willing to help any Chemistry student with their problems or doubts. I'll be glad to help you with questions regarding lab reports, designs, theory or even on how to approach the actual paper. I hope to be useful. Thanks in advance. Regards
Last reply by IBchemistry, -
Anyways.. What are your option material? I'm hopefully taking option B (Medicines and Drugs) and C (Human Biochemistry) alone. Anyone ever done both/one of them? What are yours and what do you think of them?!
Last reply by Award Winning Boss, -
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My teacher told me that an IB study guide would be very helpful going through Chemistry and I started looking online for a book. But, when I look on Half.com, there are two books for IB Chemistry, a course companion made in 2010, and a study guide made in 2007. I was wondering which is the better one to get in order to study for the IB exam and assist with explaining concepts. I am not sure what the differences are between the course companion and the study guide, so I need to know which one is better to buy. If it helps, I'm taking SL Chemistry and the teacher is very good but there are a few topics where I need to refresh on from Chemistry I (Sophomore Year).
Last reply by kirann, -
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This thread could be used for the new syllabus IA from 2016 onwards. Please note that I cannot help individual students with their IA. The choice of topic should be your own work so please do not ask for suggestions for your IA. The following information is taken from the May 2015 subject report (I'm sure it is copyrighted to the IB, but I see no harm in sharing it with IB students). Research question: Encourage students to choose a research question that has a degree of challenge, is of interest to them and one where they do not know at the outset what the outcome will be.A good research question will probably try to determine a trend or relationship. Students shou…
Last reply by IBsciencewhiz, -
- 18 replies
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With the first exams for the new syllabus coming in May 2016, you could ask questions and post resources for the option topics here. For option B, I have a complete set of videos for SL and HL. I will be working on videos for option C next. Option B SL: http://www.msjchem.com/sl-option-b.html Option B HL: http://www.msjchem.com/hl-option-b.html Option C SL (almost finished SL, now working on HL) http://www.msjchem.com/sl-option-c.html Option C HL http://www.msjchem.com/hl-option-c.html
Last reply by IB`NOT`ez, -
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Here are the links to my website and YouTube channel. I have a full range of videos for both SL and HL topics including options A, B, C and D. Website: http://www.msjchem.com/ YouTube channel: https://www.youtube.com/user/mikesugiyamajones Option A: Option B: Option C:
Last reply by Tragic Survival Chances, -
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The graph below illustrates how the vapour pressures of ethoxyethane, CH3CH2OCH2CH3, benzene, C6H6, and water, H2O, change with temperature. Using data from the graph, explain the difference in vapour pressure of ethoxyethane, benzene and water at 30 °C. ANSWER: water has hydrogen bonding; benzene has van der Waals’/London/dispersion forces; ethoxyethane has dipole–dipole forces (and van der Waals’/London/ dispersion) but they are weaker than benzene I understand the forces of each of these substances BUT how does it relate to their positions on the graph? Thanks!
Last reply by kw0573, -
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Hello all, I take chemistry HL and I need a topic for my chemistry IA new syllabus. I have suggested two ideas for my supervisor but he said they are not good. He said that the expire meant should deal with a broad topic and have qualitative data( the one with calculations) he emphasized on the point of the experiment having calculations. And he said it should relate in someway to daily life, it's good to do about food, water , cosmetics, detergins.... Any suggestions for topics???? The two topics he refused and said we're not good are: 1. The effect of temperature on the acidity of lemons 2. Something dealing with zinc half life
Last reply by torihk, -
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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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Does anyone have chemistry p1 or p2 questions specific for a certain topic in chemistry? I mostly have past papers but as I have not yet studied all the chapters in chemistry, I have a hard time trying to answer to the questions that combine knowledge from multiple topics If someone wants, I can send 95 questions with specimen answers related to Energetics and Thermochemistry
Last reply by YourFriend, -
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I just don't have much idea about how to decide my chem IA topic. There are less than 30 days till the end of my summer vacation, and I have no idea about what to do with my Chem IA. I asked my classmates about their topics, and they don't have any idea either. I still get my chem EE to write for this summer and my summer school starts at August.8th. After experiencing selecting topics for chem EE over and over again (because the chosen topics either did not fit the category of pure chemistry or were unfeasible), I find it hard to decide a suitable topic for my IA.
Last reply by IBZOMBIE9840, -
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Hi! I'm a Chemistry student currently undergoing corrections for my IA draft. I just really really REALLY need help on what the points to IB grades are. For example, how many points do I need to score from the overall rubric in order to barely reach a 7? How about 6? and so on and so forth. Thanks!
Last reply by Msj Chem, -
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Aim: The aim is to determine the concentrations of two acids and consequently the enthalpy of neutralisation for each reaction. Chemicals: NaOH 1M (standardised) HCl 2.0 M CH3COOH 2.0 M So the formulae would be: NaOH + HCl --> NaCl + H20 NaOH + CH3COOH --> NaCH3COO + H2O So basically, I added 50 cm3 of NaOH to a polystyrene cup and then put the HCl in the burette. I added successive portions of 5cm3 and saw the temperature until I reached 50cm3 of HCl Did the same for CH3COOH. Now we have to find the enthalpy of neutralisation values Questions to answer The enthalpy of neutralisation of a strong acid/base is constant. Why is the value constant? Experimental resu…
Last reply by adeljithu, -
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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, -
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Could someone please explain how I can use a database for my Chemistry IA? I just don't understand how I can use a database that is already focused on investigating something and then use it to investigate something else???? I might just be wrong about how I'm actually supposed to use a database. An example would help me understand (doesn't have to be chemistry). My chemistry teacher hasn't really explained how to do our IA and I'm running out of time.
Last reply by Rosalina, -
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Last reply by narathiel, -
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I have to finalize my chem IA topic by next week, and finding a good topic's been pretty frustrating... My teacher said a good IA's results shouldn't be easily predicted just by looking at the title, and he didn't like some topics that were too simple or too common. The ideas I'd suggested so far: Concentration of carbonic acid in soda water over time / rate of decomposition at various temperatures (seems kinda pointless...) Equilibrium of carbonic acid in water at different temperatures (link to ocean acidification? I didn't really think this through) The rate order of different acids on calcium carbonate (teacher said the acids would behave m…
Last reply by IB`NOT`ez, -
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does anyone have any ideas for an electrochemistry design lab??
Last reply by Alex1307, -
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6. The molar masses of C2H6, CH3OH and CH3F are very similar. How do their boiling points compare? A. C2H6 < CH3OH < CH3F B. CH3F < CH3OH < C2H6 C. CH3OH < CH3F < C2H6 D. C2H6 < CH3F < CH3OH The answer is D, anyone know why? I would have said A, as the difference in electronegativities between H and F are greater than the difference in electronegativities between H and O resulting in a 'more' polar molecule, hence stronger Hydrogen bonds Thanks
Last reply by Mahuta ♥, -
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Cleared up
Last reply by dessskris, -
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Last reply by Msj Chem, -
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I was doing a past exam paper, and the temperature change was 7 degrees celsius, so I converted it into Kelvin, but the answer had it in celsius. I thought that change in T was always meant to be Kelvin? Is this not the case for ib? thanks!
Last reply by turtle turtle, -
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Please help me! I am supposed to design my chemistry IA, but I honestly have NO IDEA on how to even start. Chemistry is my worst subject and I have a lot of trouble in understanding it. I always try so hard on my IA's but I always end up making B's. I have to decide on one factor that affects the rate of a reaction to investigate in my design lab IA and this lab is supposed to be easily reproducible. Here's my IA guidelines: Aspect 1 includes: Formulating a focused problem/research question and identifies the relevant variables. Aspect 2: Designs a method for the effective control of the variables. Aspect 3: Develops a method that allows for the collection of suffic…
Last reply by Chemismykryptonite, -
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Any tips/advice on how to write up the lab reports (IA's) for Chemistry? Like, anything I should/should not do? I'm in IB year 2 and I'm still struggling.. All help is highly appreciated!
Last reply by Vioh, -
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My exam is approaching and we're starting the environmental chemistry option which I find it kind of easy, but as the times are too short, my teacher will give us the choice to study the option we want, so I was wondering which of the options for HL were the easiest ones?
Last reply by wings, -
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I currently have a textbook by John Green and Sadru Damji and its making chemistry HL Hell! I'm only halfway through year one but i'm going to fail with this book. Could someone please recommend another textbook that they find favorable. Any opinions on these two books: Chemistry for the IB Diploma by Christopher Talbot and Richard Harwood or Higher Level Chemistry (Pearson Baccalaureate)
Last reply by IBsciencewhiz, -
- 1 reply
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My lab report is about calculating the neutralisation enthalpy of HCl and NaOH and then CHCOOH and NaOH. experimental results of both reactions are higher than the theoratical values and i cant find reasons to explain. There is obviously heat loss but how does this make the experimental value greater than the theoratical value? and the theoratical value is the standart molar enthalpy but my experiment was not carried out under standart conditions. Actually the initial temperature was 21 degree celcius, not 25. How does this affect the results? NEED URGENT HELP PLEASE!!
Last reply by Emmi, -
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when we are writing lab reports, we would need to compare the actual value that we get from the experiment that we conducted with the theoretical value, right? some of us might be wondering how to find literature values for enthalpy of neutralisation, especially when Google is not helping. thus, let's share literature values that we have with the sources, so when we need to find it, we can just refer to this thread. here are some that I know:
Last reply by LMaxwell, -
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Ok so the question asks, 'calculate the no. of moles of iron in 0.982g of Fe(NH4)2(SO4)2.XH2O its from a past IB exam paper. If possible, explain what to do instead of just stating the answer. Merci.
Last reply by Lilpeepforever, -
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Hello, So as the 2014 students are aware, it's exam season and i've finally got my first few days break. I have four days before chemistry. I study chemistry at HL and I have to say it is my absolute weakest subject. I've done loads of past papers and the highest i've ever got is a 4. Ideally, I would love to get a 5, but right now it seems impossible and when revising, i have no idea where to start. I was wondering if anyone had any helpful tips, tools, handy websites, or things that are essential to know for the exams. I'd be very grateful of any help! Thank you!
Last reply by leomessi, -
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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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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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I am currently forecasting for my classes next year, and I am having difficulty deciding whether or not I should I take IB Chemistry SL, due to fear of it being incredibly difficult. From upperclassmen, I have heard stories of grueling study hours and extremely rigorous exams. To place this fear into perspective, I would consider myself to be a scientifically/mathematically inclined student. I will also be taking either IB Math SL or HL. Thoughts? Opinions?
Last reply by mm8888, -
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Hi guys, this is probably a really simple question but I'm absolutely terrible at chemistry...(thank goodness I'm in SL). How do you make 1.0M of HCl from 6.0M HCl? We're doing our design labs and I'm testing the effect of concentration on the reaction time between HCl and calcium carbonate. My teacher quickly explained before we started on how to create different concentrations, mentioning ratios and water, but I didn't catch all of it. In my experiment I started off with 12mL of 6.0M HCl. The other concentrations I'm using are 4.0M, 3.0M, 2.0M, and 1.0M. So I used ratios as my teacher said to make 1.0M using 2mL of the 6.0M HCl and added 10mL of water. I'm thinking that…
Last reply by sameera95, -
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Hi I am writing a Chemistry rate of reaction IA and I am a little bit confused about what I have to do for Conclusion and Evaluation. It would be extremely helpful if anyone could write what I should include. Also, what should be the ideal length of conclusion? Thank you so much!!
Last reply by mechnight, -
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Hi all, Can someone explain to me what hybridization is briefly and how to solve this question that I'm stuck on? What is the type of hybridization of the silicon and oxygen atoms in silicon dioxide? How do you know what the hybridization is if you can't draw out the lewis structure using the molecular formula showing the bonds etc??? Thanks!
Last reply by Icekacang00, -
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Does anyone know what would be a good method of titration? I'm leaning on the side of titration with HCl and NaOH since that's what our instructor is insisting we use. Currently, if I can't get a better idea, I'll be sticking to testing antacids by placing the prescribed dosage in a known molarity of HCl.
Last reply by l0stboy, -
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Hi. I need help with my lab report about error sources. I'm investigating the effect of concentration of cathode solution on cell potential. I constructed a basic voltaic cell and used 1, 0.5, 0.1, 0.05, 0.001 M CuSO4 solution. What are some possible error sources other than the fact that that experiment was not exactly carried out under 25oC 1atm ? Also, is it a good way to leave the solutions for rest for a few minutes to make their temperatures equal with room temperature so that the initial temperature of solutions are kept constant through the experiment, for getting full marks on developing a methode to controll the variables criteria ? I cant find another way to …
Last reply by tribianni, -
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Hi everyone. Is, is chem hl much harder than chem sl? Do I have more chances to get good marks doing SL? Thanks
Last reply by just_a_student, -
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I have been tutoring Chemistry for over 2 years now and one of the topics students continually struggle with is Bonding, especially with regards to bond angles and VSEPR Theory. The key points to remember from VSEPR Theory are: - Electrons repel each other and thus spread out to minimise repulsion - Lone pairs further compress the bonding angle (I use 2 degrees as a rule of thumb) Throughout this explanation, I will be referring to negative charge centres, defined as: - A Single, Double or Triple Bond (Counts as one negative charge centre) - A non-bonding pair HL students can use this definition: - sigma bond - non-bonding pair The hard part is working out how many …
Last reply by SerUmbras, -
- 37 replies
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How would I go about designing an experiment concerning this? Thanks. Can you give me any ideas? Thanks.
Last reply by Markee, -
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Does anyone know how to determine the physcial state symbols for an equation? ie: solid (s) liquid (l) gas (g) aqueous (aq) e.g the simplest equaiton possible: 2Mg(s) +O2(g) ------->2MgO(s) Is there an actual way of knowing? I missed a few chem classes last year (Pre-IB) due to sickness Please help me:) Thanks so much:)
Last reply by Stereoisomer, -
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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, -
- 1 reply
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I'd really appreciate it if someone could fully explain to me the following question, Calcium Carbonate decomposes on heating as shown below: CaCO3 --> CaO + CO2 When 50g of calcium carbonate are decomposed, 7g of calcium oxide are formed. What is the percentage yield of calcium oxide? Thanks!
Last reply by Aninda Saha, -
- 10 replies
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In this lab I had several problems: * Concentration of CuSO4 was 0.2 M. *No major changes in temperature. Min: 28 Max: 34 *Huge percentage error of 207.38% *We had to increase the amount of CuSO4 and Zn to be able to read the temperature because the thermometer couldn´t reach it. * We used an old polyestirene cup and a normal thermal cup's lid. *Lab instructions told me to use 25 ml of 1.0 M of CuSO4 and 6 grams of zinc, but I used 75ml of 0.2M of CuSO4 and 18 grams of zinc. *The graph I plotted with the data I got from the experiment is awful. Also, I was asked to trace a perpendicular line from when the zinc was added and a tangent line from the maximum point and using …
Last reply by anabelito234, -
- 18 replies
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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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So... chemistry IA... i was wondering what is the uncertainty of pH meter? I know we may use different ones and so on and so forth but I just want to see if +/- 0.02 seems reasonable?
Last reply by Esteban, -
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Anyone have any ideas for Chemistry IA labs?
Last reply by behaaa, -
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Hey guys So I was goin over a few past paper questions and got stuck on this one:- Nitrogen monoxide may be removed from industrial emissions via a reaction with ammonia as shown by the equation below.4NH3(g) + 6NO(g) → 5N2(g) + 6H2O(l)(iii) 30.0 dm3 of ammonia reacts with 30.0 dm3 of nitrogen monoxide at 100 °C.Identify which gas is in excess and by how much and calculate the volume of nitrogen produced. Somebody please explain? Thanks in advance!
Last reply by IbTrojan, -
- 5 replies
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I have to do a Lab Report on the topic of kinetics involving the Activation Energy of a reaction by measuring the rate of a reaction at different temperatures. What I cannot get my head around is how can I find calculate the activation energy (presumably using the Arrhenius equation) without the rate constant and the Arrhenius constant of the reaction? I am quite "confuzzled" (yes, that is the extend of my confusion) and any suggestions whatsoever would be greatly appreciated.
Last reply by Drake Glau,