plmko wrote: » Yeah wouldn't mind one of those and any other mnemonics ye know
MacBizzle wrote: » What experiments can come up in question 2 so if the dichromate ones can't come up? Soap, ethene and ethyne? Is that it?
little sis... wrote: » Benzoic acid Steam distillation Ehhh yeh that's all I can think of. Still dont get how the dichromate ones can't come up though..going to study it anyway I think.
Ross31011 wrote: » Chemistry is by far my worst subject and I think I could fail. I got 32% higher level in the pre exams. Really worried because I have an awful teacher that I never did anything with. What do you think is the best stuff to study for easy marks or if you just want to pass?
EoghanIRL wrote: » Stop misleading people ! I've seen so many people say this . The dichromate questions can still be asked ! Just because the reagents are banned doesn't mean they won't ask them . They can just tell you the reagents and then ask the questions .
accountname wrote: » The ethanoic acid and ethanal preparation can't be asked, the tests for them and possibly related calculations (limiting reagents etc.) can, simples.
little sis... wrote: » Where is this stated?
Circular 0014/2011 (Discontinued Use of Chemicals – Substances of Very High Concern) informed schools of a number of substances which have been designated as Substances of Very High Concern by the European Chemicals Agency.As a result of the ban on the continued use of these substances, three of the mandatory practical activities on the Leaving Certificate chemistry syllabus could no longer be carried out by students. Since 2011, the theoretical knowledge of the experimental procedure and outcomes of the mandatory experiments listed in the circular remained as part of the syllabus, but students were not required to carry out the procedure.
CiaraMT wrote: » If they couldn't be asked then why are they still on the course?
Wanderer41 wrote: » Can anyone help with this question? It's a balancing redox reactions, simple enough, just stuck on this one part. Question is 2008 10 b) iv). Balance both equations: ClO- + I- + H+ -> Cl- + I2 + H20 I2 + S2O3 2- -> I- + S4O6 2-. Hope you can understand that. The part I'm stuck on is the second equation, for the S2O3 2- and S4O6 2-. I have the oxidation numbers as S2(+2) oxidised to S4(+5/2). I was multiplying the S2 by 2 to get the S4 but then I have the number of electrons lost wrong. How many electrons are lost? My first equation was: S2 - 1/2e -> S4 (multiply the left side by 2 as there are 4 S on the right) to give 2S2 - e -> S4. I'm obviously wrong with the 1/2 electron thing. Can anyone help with this please? Sorry if it's hard to understand. Thanks
EoghanIRL wrote: » You are wrong . Yes we can be expected to do them . They can give you the names of the reactants . . They wouldn't be on the course otherwise .
MacBizzle wrote: » No! The whole point is that we're not supposed to have done them for section A because they are dangerous. Giving us the reagents doesn't change that fact. They could come up in section B, but we won't be asked it in a question 2.
booblefoop wrote: » And to be honest there's so much controversy surrounding the experiment and whether it'll be asked I wouldn't be surprised if they left it out to avoid the hassle.
EoghanIRL wrote: » Don't study radiation . It's too dangerous . Wouldn't be surprised if they left it out to avoid the hassle .
flyboy83297 wrote: » why can't Ethanoic Acid preparation be asked in Section A? I was studying chem on my own since there wasn't enough students for a class in my school, any tips will be helpful!!! thanks : )
A7XGirl wrote: » Can someone please explain how I find the instantaneous rate of a graph?
Julius Seizure wrote: » You'll be asked for the instantaneous rate at a certain point. Find that point and draw a tangent to the graph. Then pick two points that line up neatly on your graph paper lines and give them coordinates. Rate is the slope which is (y2-y1)/(x2-x1)
