Chemistry
For Chemistry Discussions
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Hey, I'm new here and I've been struggling finding a good topic for a desgin lab in chemistry. I need to do one in electrochemistry, but it also has to be doable. I was thinking in voltaic cells but I could also do an electrolytic cell. I need help please. What factor can I change?
Last reply by sarah:), -
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When I list the materials and apparatus in my chemistry internal assessment , do I have to list things that do not affect the experiment but provide my safety during the conduction of it? For example - lab coat, goggles,protection mask?
Last reply by MainRostand, -
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I have some doubts if my research question is ok. My experiment concerned the reaction of neutralisation and the research question I have formed is " What is the enthalpy value of of the process of neutralization between NaOH and HCl? I feel this is not broad enough - all research questions I have met seem to start with the word "how".
Last reply by AgnieszkaG, -
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Hi guys , Here is the questiion can you please help me with that and explain it to me . Compare the melting points of PCl3 and PCl5 and explain the difference. Thnx
Last reply by ak18, -
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help me understand this worked example in the book as i am not able to understand the transformation from grams to the normal formula. What is the maximum volume of ammonia gas ( measured ar 273 K and 10.1 *10^5 Pa) that could be obtained from the reaction between 10g of hydrogen and 30g of nitrogen? if the actual amount of ammonia obtained is 7.05 dm^3 calculate the percentage yield for the reaction. Step 1 Write the quation for the reaction (assume the reaction goes to completion to give the maximum amount of products.) 3H2(g) + N2(g)= 2NH3(g) ( i dont get this part how did it transform from the 30g N and 10g H to this formula with these coeffecients) I would really app…
Last reply by Sandwich, -
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Hi everyone, So for my lab design I'm doing an iodine clock reaction to determine the effect of concentration on the rate of reaction between hydrogen peroxide and iodide ions. H202 + 3I(-) = 2H20 + I3(-) The I3 (-) ions react with sodium thiosulphate ions to give iodide ions which give the colour change with starch. I'm only changing the concentration of the hydrogen peroxide. If I keep all other concentrations constant can I keep the volumes of the reactant constant too? Thanks
Last reply by susanne, -
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Hi, I'm trying to write a lab design for a design lab for HL Chemistry. My general topic is 'effect of concentration on rates of reactions'. I can't do anything like reactions between HCl and Mg because according to my teacher they're 'baby' labs and wont get decent marks. I've decided to do a iodine clock reaction (H202 + 2I- + 2H+ = 2H20 + I2) with varying the concentration of H2O2. But, I'm really confused on how to write the procedure. I know the general idea, but I just don't get how you would actually do the lab. Does anyone know a good method for this lab? Thanks
Last reply by sameera95, -
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when you have to find the concentration of a solution and only a volume is given to you...how do you find the concentration? thanks in advance!
Last reply by Icekacang00, -
Are colorimeters commonly found in high school labs?
by Guest Sunshine123- 8 replies
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Hey! I am currently working on a reactions rate design lab, and I am thinking about doing something with colorimetry to measure the intensity of color. But then since our school don't really have a colorimeter and I can't find a lot of information on it, I would just like to confirm whether colorimeters are meant to be common lab equipment to be found in high school laboratories? Thanks in advance!
Last reply by n00l3, -
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For all those studying chemistry, this is a list of all the online resources that I have found to help me. I hope that they help you too. IB Chemistry Blog, by Dr Liakatas - This site has handouts for all the topics and goes through key definitions. Kstruct IB notes, by Matthew Shepherd - Fairly comprehensive set of notes by a former IB student (1998). Chemactive lessons and notes - Set of lessons and and notes for IB chemistry. Notes and powerpoints, by Adam Skagen - Powerpoints for chapters 1-10, with two option chapters. SL Chemistry notes - Notes specifically for the standard level specification Chemistry notes, by Mr Schultz - Notes on varied chapters, but incomplete…
Last reply by Karan888, -
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I am working on a chemistry IA, and I have a few questions about the uncertainties bit. We weighed a alcohol burner with a 0.01 scale. (the first one weighed 147.09g). We burnt it for a set amount of time, and weighed it again (it then weighed 146.45g). Which part do I use to calculate the uncertainties/how do I do it? Thanks in advance!
Last reply by Sapnil Mohanty, -
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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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I've been on this problem for hours now, and I really need some help. "Acetic acid, CH3CO2H, is the solute that gives vinegar its characteristic odor and sour taste. Calculate the pH and the concentrations of all species present (H30+, CH3CO2-, CH3CO2H, and OH-) in 1.00M CH3CO2H."
Last reply by Emmi, -
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Hello everyone! I have problem with my Design project in IB Chemistry HL. My research question is: how does the concentration affect the value of experimentally determined enthalpy? I have collected the necessary data, I've created a graph of temperature change versus concentration - it shown the positive linear correlation. After that I have plotted the graph of enthalpy change versus number of moles. As we know, enthalpy is amount of heat changed per mole of a substance. It does not change with the number of moles, it is a constant. Thus, the graph should look in the form y=c, where c=const. Now my question is: How to calculate the uncertainty of that graph? Should I us…
Last reply by bluedino, -
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Hi I am doing my extended essay on chemistry and my topic is the different concentration of flavonoids on different leaves of tea. So the problem is that i cant find any type of experimentation my school has acces to, so it will be good if any could give me any suggestions. Thanks in advance.
Last reply by alefal, -
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Hi guys, I have a problem in doing the pathway in Hess Law of Na2CO3 and NaHCO3 can you please help me out . thanks very much
Last reply by mesadoc, -
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How much harder is HL? What are the main differences between the two courses?
Last reply by Sandwich, -
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I can easily finish 3 out of 3 questions in section B in paper 2. If I do this would the best of three be taken or how will I be marked??
Last reply by jsm_95, -
Chemistry design lab report help
by Guest clod_the_IB_COD- 2 replies
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For my design experiment I wanted to see the effect of temperature on the current of a reaction at equilibrium. I would measure this for several different reaction. My teacher said this is too simplistic and told me to work out the equilibrium constant instead. I do SL chemistry and do not know how to work out the equilibrium constant. Do you think this idea is too simplistic or should i continue with it? Also my main focus for this IA is just to get full marks in the Design aspect. Thank you,
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I'm a bit lost - what does it take for a decent chem EE. any help will be appreciated! Okay .. well my independent variable is time ... is there an uncertainty for that?
Last reply by sarah:), -
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Alright, so I have this chemistry assignment on electrolysis used to solve a global problem. I chose to address the issue of hydrogen being used as a fuel cell as a byproduct of electrolysis. I wanted to know some of the advantages and disadvantages of the political factor of this. I have the many positives and negatives for environmental factors. The political factor is a bit tricky. I know that dependence on the Middle East and other countries producing oil will decrease and that availability would become more widespread. Any other information or ideas are acceptable.
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So, I have been asked to write my first Lab Report for the chemistry class. I have written a few lab reports in another format in the past, but this is my first IB one. The teacher only asked us to write the Design section but I'm having trouble indentifying the variables for the experiment I came up with. I want to use my knowledge about yields (experimental vs theoretical yield) to get the percentage yield of hydrogen production when reacting Alkali metals with water. It is simple enough, but what I want to do is to compare at least three different alkali metals (say Lithium, Sodium and Potassium) and collect the hydrogen produced from each of them, which would be the …
Last reply by MainRostand, -
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Hello, IB-people. I'm taking Chemistry HL, my plan is to write an EE about Acids and Bases. I have a list of good sources but what bugs me most is what I should research. So what do you think would make a good research question, my friends?
Last reply by Tsuun, -
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Hey guys! during the upcoming week I will conduct my Design experiment. We start on tomorrow on Monday. I have chosen topic connected with energetics and enthalpy change. i am investigating one factor that affects the experimentally determined enthalpy - in this case it is concentration of one of reactants. I've sent the Design recipe to my teacher a week ago, today she gave me a feedback in which she suggested slightly changing the title and some sentences. In general, she said I know what to do and how to conduct an experiment. But my biggest problem is with the equation and identifying the variables. as we know the equation for enthalpy change is ΔH=Q/n. I have convert…
Last reply by CkyBlue, -
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I desperately need someone's help who is good at everything in quantitative chemistry! It is the first unit and I have my unit test tomorrow but I do not understand anything! My teacher has tried to help me and I get it when he is explaining (somewhat at least) but when I go to work on them myself it makes no sense! Please help me!
Last reply by susanne, -
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Hey! I have a doubt about relative uncertainties in the internal assessment... If you have to divide two values with one another. Say A/B. A has an uncertainty of 13.7% and B has an uncertainty of 4.1377%. I heard that the uncertainty must be rounded to one significant figures. So does that mean rounding them before giving 10%+4%=14% or 13.7%+4.1377%=17.8377% then rounded to 1 sig fig giving 20%? I would really appreciate any help. Thanks
Last reply by Wicquor, -
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I have been out of the country for a while and plan to go back this year starting IB1. Choosing the subjects was challenging and I ended up choosing Chemistry HL because I was told that if I want to study medicine I should take HL since the majority of universities wish it. I would gladly take Chemistry HL, but I have doubts concerning my abilities on the subject. In the school I am in at the moment is a typical Chinese school and the teacher says that I am three years behind my other classmates. I would feel better if I choose Chemistry SL but the result would be choosing English A HL, and this is where I am not so sure I can do well in. I have always gotten average gra…
Last reply by susanne, -
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does anyone know how much a drop of universal indicator weight? I've kind of lost my data for this
Last reply by -._._.-, -
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I was thinking of doing an EE on Preservation technique to prevent browning of apples but my teacher said it was too simple and too biology-ish, is there a way that i can change this topic to fit chemistry?
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does anyone have any idea for a Chemistry EE research question? thanks in advance.
Last reply by Sandwich, -
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So, i was pretty set on taking Chemistry until 10 minutes ago when I heard someone say that Chemistry was harder than Physics. I don't really have a preference, to be honest I'm not much of a science person and I really just want to get a good grade... I would be taking either subjects at Standard Level.
Last reply by -._._.-, -
Please help me, I need to create an experiment (a plan) and the aim is to determine the volume of M(Zn) by changing the mass of Zn. Also, I need to find out the molar mass of Zn. Please help!!! Stoichiometry; D, E and F.doc
Last reply by Malak96, -
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So I did an experiment, and I think for one of the % composition for Mg, there was a 41.7% percentage deviation o.o So huge, I got pretty upset but I guess there's room for discussion. I just have a question about crucibles, does using a new crucible affect an experiment in anyway, just thought I'd give anything a shot.
Last reply by Siger, -
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I'm writing up my first Chemistry IA. The lab was a design lab on the rates of reactions. I combined different concentrations of magnesium to the same concentration of HCL and measured the gas produced. My problem is, even though I could see a lot of gas being produced, the force of the gas wasn't strong enough to move the gas syringe. Will this result in poor marks on my IA for not getting any results??? My teacher is very new to IB but says that IB is only looking at my method and for changes I think I should make if I were to repeat the experiment. Is that true? Or will I receive a bad mark?
Last reply by Abhishek Mishra, -
Saponification - what exactly is it?
by Guest Sunshine123- 1 reply
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Hello! I am currently completing a reactions rate design lab for chemistry; I wanted to investigate the rate of saponification between ethyl ethanoate and sodium hydroxide, however, I don't really know much about this reaction. If you have ever done this reaction at school, can you describe what I should expect in the reaction? (Eg in what concentration does ethyl ethanoate usually come in? What will the reaction look like?) Your help will be very much appreciated!
Last reply by cricketcrazynerd, -
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Im a student in IB1. In our school we have to choose whether we want SL or HL in our subjects at the end of our first year of IB. I want to study medicine. The subjects I've signed up for next year are: ITGS SL Math Studies SL Bio HL English A1 HL Arabic B HL I also take chemistry but im having trouble figuring out whether SL or HL is the right choice for me. Can someone please help me? My current grade in chemistry SL is 72%. That's a 6 out of 7. I want to take chemistry HL but I'm afraid because it might be too hard. PLEASE HELP! Thanks in advance
Last reply by Neeraj Chawla, -
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Ok, in lab I did an "experiment" in which we had to separate a mix that had three 3 chemical compounds (NaCl,NH4Cl, SiO2) the mix weighed 1.5 grams. After separating them we had results, and after repeating it several times we had different results. For example in try 1 we had 30% NaCl, 20%NH4Cl, 49%SiO2 in try 2 we had 33%NaCl, 21%NH4Cl, 45%SiO2... But what would be my dependent and independent variable? The original mix is always the same (1.5 grams), but the percentages changes because our procedure isn't 100% the same, so is there an independent?
Last reply by Yolo Swaggins, -
Hess's Law
by Kesh19- 1 reply
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Hi guys, This is the experiment i am carrying out. Can you please help me in telling me what to put in the hypothesis Aim: To determine the molar enthalpy change of formation of hydrated copper sulphate from anhydrous copper sulphate by referring to Hess's Law of constant heat summation thnx Kesh19
Last reply by Emmi, -
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I really need some good revision notes for IB chem and I can't seem to find anything useful online that covers all the topics. The textbook is too detailed to go over completely again. My mock is tomorrow, freaking outttt.
Last reply by dniviE, -
Do hydrated and anhydrous salts react differently in reactions?
by Guest HayashiEsme- 1 reply
- 594 views
Just asking out of curiosity, does the water molecules affect the reaction in any way? and how are the water molecules bonded into the salt? Thanks!
Last reply by RainAL, -
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I know that a colorimeter/spectrophotometer give absorbance values and that represents the amount of light absorbed rather than transmitted.. but is it possible to use those devices to measure solubility? If so, how? What is the relationship between absorbance and solubility? I think the relationship is absorbance values decrease solubility decreases or vice versa but I am not entirely sure. Thank you very much:)))
Last reply by SurajM, -
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My teacher chose food chemistry as one of our options. Does anyone have any revision material or notes they could give me? Or any place that could help me revise for that chapter?
Last reply by SurajM, -
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Hi! I need some help with calculating the uncertainty for my lab report. If there is an uncertainty of ±1 second on a measurement of time in seconds ( e.g 120s ±1) and the time is converted to minutes, what does the uncertainty become? (2 minutes ±?). Thanks
Last reply by chaoticmadness, -
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Hello everyone! I urgently need your help on this. At school my chem teacher taught the class options D and E. However, I can't understand option E so I have just started to study option A which looks more interesting to me. Am I allowed to do this? I mean will it be okay if I do option A and D while my peers are doing option D and E? Will the IB notice it and mark me down or something?
Last reply by Gaby, -
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I just conducted a lab on determining the molar enthalpy of a certain salt. The value that I found experimentally was 7 kJ/mol, whereas the theoretical value was -160 kJ/mol (I know, extremely off) What would the percent error be? I've never dealt with negative values when it came to these calculations. Would it just be |-167|/-160=-104% error? Is a negative percent error possible? Thanks
Last reply by TogoPogo, -
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so, i want to do the design internal assessment with redox as my topic, but i am not sure if i'm doing it right... the idea is to heat up dry cell with heat plate. i am trying to investigate the difference in voltage my question is: 1. will it count as redox experiment and not kinetics experiment? 2. will it be safe? and if it is do you have any suggestion to improve? thanks for help
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How do you make sure that the temperature of your compounds remain the same during a lab?
Last reply by CkyBlue, -
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If anyone has any helpful websites or books i could look into for extra help and understandign of the topics in chemistry because i dont have a very good teacher so i need help understanding the topic betterr )
Last reply by sunny.shah, -
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I have a buddy thats still doing the IB and he wanted to know what he should do for his IA. Its what affects the volume of a drop from a pipette or a dropper of sorts. He said something about density or temperature but he had no idea what or how to set the experiment. I was thinking he should do temperature, as a heat/hot plate would be sufficient and just room temperature and 30, 40, 50 degrees celsius. (Not sure about Fahrenheit) I was suggesting him do this but the question is the variable in temperture and the temperature would decrease as you go along in the trials. Also heat and plastic pipettes? not sure Density would be good, but i was thinking and got stuck on wh…
Last reply by CoryAlpert, -
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I need help study chem and making notes, and revision
Last reply by Lero,
