Popular Post dessskris Posted February 27, 2011 Popular Post Report Share Posted February 27, 2011 10 Reply Link to post Share on other sites More sharing options...
alramsey Posted July 13, 2011 Report Share Posted July 13, 2011 (edited) i found this site as well, maybe it could help http://www.saburchill.com/physics/chapters/0070.html Edited July 13, 2011 by lanthanoider 2 Reply Link to post Share on other sites More sharing options...
Nik Mitchell Posted November 6, 2011 Report Share Posted November 6, 2011 Very useful thanks. However, I would like to point out that the uncertainty associated with a ruler is slightly different, because there is uncertainty associated with measuring with each end, so the +/- 0.5 cm would apply twice, bringing the total uncertainty to +/- 1.0 cm. Reply Link to post Share on other sites More sharing options...
LMaxwell Posted November 23, 2011 Report Share Posted November 23, 2011 I'm writing my 3rd chemistry report and I want it to be good (this is for the DCP). So here's my question: do I propagate the results and show the calculations? If so, do I talk about them or do I leave that until the Conclusion and Evaluation? Also how would I display the uncertainties... in brackets next to the manipulated data or as a separate table showing the uncertainty on each piece of equipment? I ask this because I read something on the internet which confused me: When the internal assessment criteria are applied to investigations, the issues of errors and uncertainties must be interpreted. You need to be able to make statements about the minimum uncertainty, based on the least significant figure in a measurement, and can also make statements about the manufacturer's claim of accuracy. You must be able to estimate uncertainties in compound measurements, and make educated guesses about uncertainties in the method of measurement. If uncertainties are small enough to be ignored, the candidate should note this fact. Higher level candidates should also be able to express uncertainties as fractions and as percentages. They should also be able to propagate uncertainties through a calculation. Please refer to the handout “Errors and Uncertainties” for some specific examples of the propagation of errors. Source: http://web.me.com/dbyrum/Ris/Resources/page29/files/IB_LabReport.pdf Thanks (whoever answers) Reply Link to post Share on other sites More sharing options...
dessskris Posted November 23, 2011 Author Report Share Posted November 23, 2011 I'm writing my 3rd chemistry report and I want it to be good (this is for the DCP). So here's my question: do I propagate the results and show the calculations? If so, do I talk about them or do I leave that until the Conclusion and Evaluation? Also how would I display the uncertainties... in brackets next to the manipulated data or as a separate table showing the uncertainty on each piece of equipment? Thanks (whoever answers) you do need to show your working, equations and calculations. show them in the Data Processing section. in the list of materials and equipments, I do write the uncertainty of each equipment (where appropriate) in Data Collection and Data Processing sections, indicate every uncertainty next to the data in the working. however note that you only need to show the working once (where there are repeats) and then you show the results ONLY for the repeats, in a table. so then in the table you can put one column for uncertainties, or if they're the same just put it in the heading of the column for the data. 1 Reply Link to post Share on other sites More sharing options...
LMaxwell Posted November 24, 2011 Report Share Posted November 24, 2011 (edited) Hi again. I'm doing an experiment where I have to find the number of water molecules in anhydrous crystals (which I've done).I've also found all the absolute uncertainties on my equipment and put them into percentage error, then added them together to find total percentage error. What do I do with this percentage error to find the uncertainty of my experiment?Thanks Edited April 2, 2012 by brofessional Reply Link to post Share on other sites More sharing options...
dessskris Posted November 24, 2011 Author Report Share Posted November 24, 2011 wrong... don't just add them ALL together. for each calculation, you need to deal with the relevant uncertainties. the uncertainty for the final result will be the unc of your experiment. Reply Link to post Share on other sites More sharing options...
Sabs44 Posted December 8, 2011 Report Share Posted December 8, 2011 Hi again. I'm doing an experiment where I have to find the number of water molecules in anhydrous crystals (which I've done). I've also found all the absolute uncertainties on my equipment and put them into percentage error, then added them together to find total percentage error. What do I do with this percentage error to find the uncertainty of my experiment? Thanks for reading Try this tool: http://ibsurvival.com/uncertainties/index.php 1 Reply Link to post Share on other sites More sharing options...
Christina perera Posted May 30, 2012 Report Share Posted May 30, 2012 Okay so I have 3 sets of data, when i average them , what happens to the uncertainty? Reply Link to post Share on other sites More sharing options...
dechengirl Posted June 7, 2012 Report Share Posted June 7, 2012 i need to start with chem internal assessment. Are we supposed to design a new experiment or just replicate? How do I start? Reply Link to post Share on other sites More sharing options...
sciHL Posted October 20, 2012 Report Share Posted October 20, 2012 here is practice chem lab i did http://www.ibsurvival.com/files/file/2481-hess39-law-practical/ Reply Link to post Share on other sites More sharing options...
Chicken_Jose Posted February 12, 2013 Report Share Posted February 12, 2013 Helped me go erase some errors in my IA'sDOs&DONTs.pdf Reply Link to post Share on other sites More sharing options...
MWL Posted December 30, 2014 Report Share Posted December 30, 2014 SHOULD THE RESULTS BE ROUNDED ONLY IN THE END OF THE CALCULATION OR THROUGHOUT THE ENTIRE CALCULATION? Reply Link to post Share on other sites More sharing options...
Chirag Hablani Posted February 8, 2015 Report Share Posted February 8, 2015 I have my final lab as DCP and CE on heat of fusion. I Have done the stasticial analysis of data and I have not drawn a graph to show how I obtained my final answer? If I draw a graph now, I get different answers for statistical analysis and gradient of graph. What to do? 1 Reply Link to post Share on other sites More sharing options...
Tom Hiddleston Posted February 25, 2015 Report Share Posted February 25, 2015 If there's one thing to remember, it's to remember: the simpler the better. However, you can't make it too simple. It's all about the balance. Reply Link to post Share on other sites More sharing options...
Ado Laplana Posted March 14, 2015 Report Share Posted March 14, 2015 I have a question. i'm chemistry HL, and I plan to submit as a DCP my investigation on Hess's Law. I want to make sure if graphs are REALLY REQUIRED for DCP to get full marks. Would an IA that merely involves determining specific values of substances for example, determining enthalpy change of decomposition, be rendered invalid and not give me full marks? Reply Link to post Share on other sites More sharing options...
kristinemjs Posted April 10, 2015 Report Share Posted April 10, 2015 Hi, I need help with something for my Chem IA, and I would be very happy if you could take a look at my post:http://www.ibsurvival.com/topic/33704-internal-assessment-topic-for-chemistry-hl/#entry236271 Thanks! Reply Link to post Share on other sites More sharing options...
Fare1504 Posted August 26, 2015 Report Share Posted August 26, 2015 Hi people,I have a question about chem IA. We still didn't do any of chem lab reports and in few days I'm gonna be in IB2... I know that this isn't good but I don't know what to do!Can anyone explain me what is the IA in chem, how do we do it?Thanks a lot Reply Link to post Share on other sites More sharing options...
Msj Chem Posted August 27, 2015 Report Share Posted August 27, 2015 Hi people,I have a question about chem IA. We still didn't do any of chem lab reports and in few days I'm gonna be in IB2... I know that this isn't good but I don't know what to do!Can anyone explain me what is the IA in chem, how do we do it?Thanks a lot The IA is the new syllabus is an individual investigation. You have to decide on the topic, carry out an investigation and write it up. This is just a very brief outline - you should ask your teacher for more details or see the guide I posted on this forum. It is normal for students to carry out the investigation in the second year of the course as this gives them time to develop their skills and cover enough of the curriculum. I would expect that you will carry out your investigation in the second year, but if you are worried, then speak to your teacher or the DP coordinator at your school. Reply Link to post Share on other sites More sharing options...
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