wendy391 Posted November 9, 2011 Report Share Posted November 9, 2011 Did anyone find a weird question in MCQ that made no sense: it was about the increasing order of boiling pt of ethane, chloroethane etc that one..?NOTE: There is to be NO discussion of Chemistry Paper 3 on this thread. Paper 3 may not be discussed until 1PM GMT 9/11/11. 1 Reply Link to post Share on other sites More sharing options...
Kydas Posted November 9, 2011 Report Share Posted November 9, 2011 Thoughts on both papers?I personally found paper 1 quite easy. Paper 2 seemed straightforward but after the exams I realised I had committed a lot of ridiculous mistakes. So I was disappointed with that. Aside from the mistakes I thought it was okay. Reply Link to post Share on other sites More sharing options...
Schrödinger's Cat Posted November 9, 2011 Report Share Posted November 9, 2011 (edited) I think it was OK - out of what I did I only left one answer blank (drawing bloody silicon dioxide, lol) so the paper was actually a lot better than I had anticipated. Which Section Bs did you do? I did the one on redox and the one on energetics Edited November 9, 2011 by Schrödinger's Cat Reply Link to post Share on other sites More sharing options...
nevermore2010 Posted November 9, 2011 Report Share Posted November 9, 2011 i think they are quite easy. But there is one question where I really stuck on paper one which was about the graph and whether it was electronegativity, ionic radius, atomic radius, or something else. I dont even remember which answer i put. I literally finish on paper one in 30 minutes or less, and paper two in about 70 minutes including the re-evaluating. Which was actually creepy, it made me think that there should be something wrong with me, but i already like recheck everything over again. I think I did all question from 1 through 7, not really sure which was which. Reply Link to post Share on other sites More sharing options...
wendy391 Posted November 9, 2011 Author Report Share Posted November 9, 2011 I thought paper 1 was harder than usual I nearly ran out of time ^ and for that graph, it definitely couldnt be electronegativity or melting point, so i chose atomic radius between the two choices.. But how about the one about increasing boiling point of the following molecules: ethane, chloroethane, Bromoethane and iodoethane? Shouldnt the order be ethane < Idoethane < Bromoethane < chloroethane ? But there wasnt a choice for that, I was so confused!!! Paper 2 was pretty easy except I made a stupid mistake in the ideal gas equation in section A... Overall, I was satisfied with my performance haha Reply Link to post Share on other sites More sharing options...
wendy391 Posted November 9, 2011 Author Report Share Posted November 9, 2011 I think it was OK - out of what I did I only left one answer blank (drawing bloody silicon dioxide, lol) so the paper was actually a lot better than I had anticipated. Which Section Bs did you do? I did the one on redox and the one on energetics I did the redox too! and another one had hybridization.. I dont quite remember the exam now Reply Link to post Share on other sites More sharing options...
Schrödinger's Cat Posted November 9, 2011 Report Share Posted November 9, 2011 I thought paper 1 was harder than usual I nearly ran out of time ^ and for that graph, it definitely couldnt be electronegativity or melting point, so i chose atomic radius between the two choices.. Yeah Paper 1 was harder than the practice ones I'd done and I almost ran out of time too! Look at the difference between atomic radius and ionic radius: I don't even actually remember what the graph was now but I think it was atomic radius hahaha. Damn. And I don't actually remember the boiling point one at all... I did the redox too! and another one had hybridization.. I dont quite remember the exam now Hybridisation? Was that the bond angles one? I wanted to do that one until I saw the organic bit... oh lawdy Reply Link to post Share on other sites More sharing options...
JenRice Posted November 9, 2011 Report Share Posted November 9, 2011 But how about the one about increasing boiling point of the following molecules: ethane, chloroethane, Bromoethane and iodoethane? Shouldnt the order be ethane < Idoethane < Bromoethane < chloroethane ? But there wasnt a choice for that, I was so confused!!!This was in the SL exam as well.I checked the boiling points on wiki...apparently it was ethane(-89)< chloroethane(12.3)< bromoethane (38.4)< iodoethane (72.4)don't really see how they expected us to know that though, I assumed that the more electronegative the halide, the larger the dipole dipole difference and hence the highest bp. Reply Link to post Share on other sites More sharing options...
wendy391 Posted November 9, 2011 Author Report Share Posted November 9, 2011 But how about the one about increasing boiling point of the following molecules: ethane, chloroethane, Bromoethane and iodoethane? Shouldnt the order be ethane < Idoethane < Bromoethane < chloroethane ? But there wasnt a choice for that, I was so confused!!!This was in the SL exam as well.I checked the boiling points on wiki...apparently it was ethane(-89)< chloroethane(12.3)< bromoethane (38.4)< iodoethane (72.4)don't really see how they expected us to know that though, I assumed that the more electronegative the halide, the larger the dipole dipole difference and hence the highest bp.Oh thanks God I answered that one! but Im pretty sure Chlorine is more electronegative than Iodine because of the shielding effect of iodine ... it just doesnt make sense... Reply Link to post Share on other sites More sharing options...
wendy391 Posted November 9, 2011 Author Report Share Posted November 9, 2011 I thought paper 1 was harder than usual I nearly ran out of time ^ and for that graph, it definitely couldnt be electronegativity or melting point, so i chose atomic radius between the two choices.. Yeah Paper 1 was harder than the practice ones I'd done and I almost ran out of time too! Look at the difference between atomic radius and ionic radius: I don't even actually remember what the graph was now but I think it was atomic radius hahaha. Damn. And I don't actually remember the boiling point one at all... I did the redox too! and another one had hybridization.. I dont quite remember the exam now Hybridisation? Was that the bond angles one? I wanted to do that one until I saw the organic bit... oh lawdy Hopefully its atomic radius!!! haha And yes i think so... the one that u needed to draw two Lewis structures and predict the bond angles. But i dont remember doing anything organic lol Reply Link to post Share on other sites More sharing options...
Schrödinger's Cat Posted November 9, 2011 Report Share Posted November 9, 2011 Oh that boiling point one! It's because iodine is the biggest atom, because boiling point didn't depend on electronegativity but intermolecular forces (van der Waals)... Reply Link to post Share on other sites More sharing options...
wendy391 Posted November 9, 2011 Author Report Share Posted November 9, 2011 Oh that boiling point one! It's because iodine is the biggest atom, because boiling point didn't depend on electronegativity but intermolecular forces (van der Waals)... ok..thank you!!! U saved me out of the confusion hahah Reply Link to post Share on other sites More sharing options...
Revenge Posted November 9, 2011 Report Share Posted November 9, 2011 I thought paper 1 was harder than usual I nearly ran out of time ^ and for that graph, it definitely couldnt be electronegativity or melting point, so i chose atomic radius between the two choices.. Yeah Paper 1 was harder than the practice ones I'd done and I almost ran out of time too! Look at the difference between atomic radius and ionic radius: I don't even actually remember what the graph was now but I think it was atomic radius hahaha. Damn. And I don't actually remember the boiling point one at all... I did the redox too! and another one had hybridization.. I dont quite remember the exam now Hybridisation? Was that the bond angles one? I wanted to do that one until I saw the organic bit... oh lawdy Hopefully its atomic radius!!! haha And yes i think so... the one that u needed to draw two Lewis structures and predict the bond angles. But i dont remember doing anything organic lol I thought it was ionic radius, because the graph excluded all the noble gases, and if it was atomic radius the noble gases would have be included on the graph, but I dont know, that paper 1 had to many dodgy questions for my liking. Reply Link to post Share on other sites More sharing options...
Schrödinger's Cat Posted November 9, 2011 Report Share Posted November 9, 2011 I picked ionic radius too because of that reason. But with chemistry I'm never sure of myself haha~ Anyone who did the energetics question - what activation energy did you get? It's just my friend got a much smaller value than I did - we both saw the trick of the 1/T being x 10-3 and we used the same method, but we still got different answers. Haha I'm not so fussed about the answer so much because I know the method was right but I'm just curious Reply Link to post Share on other sites More sharing options...
nevermore2010 Posted November 9, 2011 Report Share Posted November 9, 2011 (edited) oh god. physics hl was so bad (for me) that i cant even remember any of the good time i had in math hl and chem hl. darn, i really can't wait to get the my crappy score Edited November 9, 2011 by nevermore2010 Reply Link to post Share on other sites More sharing options...
Kydas Posted November 9, 2011 Report Share Posted November 9, 2011 I think most people got the silicon dioxide structure wrong. I had the activation energy question all muddled up in my head. Reply Link to post Share on other sites More sharing options...
wendy391 Posted November 9, 2011 Author Report Share Posted November 9, 2011 I thought paper 1 was harder than usual I nearly ran out of time ^ and for that graph, it definitely couldnt be electronegativity or melting point, so i chose atomic radius between the two choices.. Yeah Paper 1 was harder than the practice ones I'd done and I almost ran out of time too! Look at the difference between atomic radius and ionic radius: I don't even actually remember what the graph was now but I think it was atomic radius hahaha. Damn. And I don't actually remember the boiling point one at all... I did the redox too! and another one had hybridization.. I dont quite remember the exam now Hybridisation? Was that the bond angles one? I wanted to do that one until I saw the organic bit... oh lawdy Hopefully its atomic radius!!! haha And yes i think so... the one that u needed to draw two Lewis structures and predict the bond angles. But i dont remember doing anything organic lol I thought it was ionic radius, because the graph excluded all the noble gases, and if it was atomic radius the noble gases would have be included on the graph, but I dont know, that paper 1 had to many dodgy questions for my liking. ah i didnt notice that the graph excluded all the noble gases.. but noble gases do not form ions so shouldnt it be the other way round? but apparently all noble gases do not have both ionic & atomic radius according to the data booklet... i dont know!! Reply Link to post Share on other sites More sharing options...
saunders is god Posted November 10, 2011 Report Share Posted November 10, 2011 Noble gases don't form ions because they're noble gases ergo the answer was ionic radius. Of course, noble gases have an atomic radius, ( they're atoms ) and since the graph had points missing corresponding to noble gases, the answer had to be ionic radius Reply Link to post Share on other sites More sharing options...
xxshame Posted November 10, 2011 Report Share Posted November 10, 2011 Chem paper 1 was horrible... paper 2 was slightly better. The data-analysis question was terrible though. Did anyone find their answers were very small numbers? like to the power of -7 and etc? Also, what was the reason that sodium had to be removed from the reaction? I had no clue for that one. For section B I did the bonding/periodicity one and the redox. The funny thing was that I spent half the year saying how much I hated redox, but I ended up answering the redox question on the exam. It was fairly simple, just voltaic cells and electroplating! I expected electrolytic and electrolysis of aqueous solutions but thankfully the IB were kind to us Reply Link to post Share on other sites More sharing options...
ZiggyM Posted November 10, 2011 Report Share Posted November 10, 2011 I can hardly remember paper 1 now! I never know how I go with it, multiple choice is always my worst!! I put atomic radius for that graph question as well. I did the organic question and the one that had energetics and rates (I think?) So long ago now! I didn't actually find them all the bad, and assuming I did them right even the organic was quite nice! I absolutely hate redox - cells really don't work for me ! That's why I didn't do the redox question I was so annoyed that acids and bases came up in section A - I was trying to avoid it ! How did everyone find paper 3? I did the Biochem and Enviro options - Biochem was fine but enviro had wayyyy too many equations for my liking! I couldn't remember half of the mechanisms, I suppose that's what you get for not having time to study for it until the night before!! Reply Link to post Share on other sites More sharing options...
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