Preparation for Chemactivity 2

hello students in organic chemistry this is going to be the first up my youtube videos forget preparing you for Chem activities this is for Chem activity to be performed on Wednesday me I'm September 26 before we get started I'd like to talk a little bit about why I keep guided inquiry is so worthwhile why I doing why have you back by the books and spend your class time doing most people don't necessarily like guided inquiry they're not necessarily comfortable with working in groups and they would rather just have a passive learning experience but as you can see from this chart people owe me learned small amounts to remember small amounts of what they knew we'd see or hear com a very good lecture might provide lots of opportunities to see and here in which case the passive learning is still happening and a person might be able to you something that material again but only 50 percent of what they see and hear matters it's also well known that people tune out after bad eight or nine minutes of a lecture unless there's some interactivity however with active learning you can learn much more and retain much more and use it in much more creative ways then you can with passive learning this sad model love learning is ever sell too many years up study in education specifically why we use process-oriented guided learning it works very well for science courses content AP courses in general guided inquiry facilitates earning higher grades people at the top but the scaler probably can turn their eighties anyway but this guided inquiry has been shown improved again and again to help the people who are struggling more than the people at the very top guided inquiry also leads to greater retention material I've seen it my own and students in our chemistry major courses we give comprehensive exams one or two or three years after we complete a course and the courses that I D is guided increase wanted the teaching methods those students have done better on the comprehensive exams than students before that time it's a good use a class time why should I spend my class just telling you which you can go learn from reading more web tutorials and so on should damn use the class time actually learn where your misconceptions are 2:38 and how to do things better it leads to a more thorough understanding at the material it's not just a bunch of facts that you write down and then regurgitate you actually have to use the material to stay to answer the questions and possibly more most importantly it builds group dynamics a Braille to support system within the class em it com helps you learn to work in a group the soft skills are things that %uh employers in every field me working in teams as part of the modern world sup in order to make your Chem activity most useful during the class period there are certain things we need to keep in mind first and foremost disrespect expect everybody to respect each other to respect me and I will do the same for you comments important to treat each person in their ideas arm with the appropriate respect you need to assign someone as a group manager and each time you meet you can pick a different person for this role but the group manager will kinda keep people focused and keep the conversations from wandering away or they progress from slowing everyone in the group should have a workbook or photocopy of the chem activity so that they can read the reading sections and then discuss the problems properly and everyone should attempt to write down the answers as we go you should and a given class period were quickly through the easier material there's no reason to spend time with you already all no but you should however stop an address each people's persons questions and make sure everybody understands finally I will provide clicker questions to help keep you on track okay the second part in this video is going to be at home a brief review up lewis structures and formal charges to prepare you for doing this yourself on and I picked the carbonate ion c2 h3 home two-minus as my example and when you do lewis structures you have to consider how many Adams you have and how many valence electrons there are on each app so for example carbon AZT four valence electrons and their two carbon atoms there are three hydrogen atoms each of them has one bill its electron and there too oxygen atoms each of which has six billion select tracks and finally because there's a -1 charge there's one extra electrons K -1 charge means and excess electron charge by one now when we go to make lewis structures which we need to share electrons in order to make the second row elements have Oct at and the first row elements like I pigeons have do it or to look 8 or two valence electrons around they can have these valence electrons from the electrons they originally have as Adams and by sharing those electrons in organic chemistry normally the carbons are bound together so we can start by drawing the two carbon atoms next to each other one carbon atom brings one electron the other carbon atom brings one electron and together they share a pair of electrons to make Obama each other's carbons also has three additional valence electrons that is not involved in the sharing now there are several possible ways to draw a correct lewis structure for this formula I'm in a car concentrate on the one that equals Carpani when that equals carbonate has both oxygen atoms attached to the same Carmona so one of the oxygen atoms would share one of its unpaired electrons with carbon like so the other oxygen atom could share a second unpaired electron with an oxygen atom like so 5 that it still has for itself and this is the basis a molecule we still have hydrogen atoms to put in hydrogens because they can only form one one bond always end up on the outside where the end chains should start putting in those hydrogens to fill in everyone's valence this carbon has an unshared electron it can share it that electron with one of hydrogens electrons to make a carbon hydrogen single bond can do that again you can do that again and now the carbon atom on the left has a total up to 46 8 valence electrons and it has an octet each of these hydrogens has to do it but we have not done first off we have still haven't oxygen that Scott a single-electron oxygen with the single-electron a carbon with the single-electron we have no more hydrogen atoms to make bombs with at this point when we have extra bonding sites and no more external Adams to put an we start talking about multiple bonds so madge in the electron down here one-electron from carbon one-electron from oxygen forming a second bond that would make the net double bond between carbon an oxygen K so now this carbon has two for 6 8 balance electrons and all were left with Isis oxygen which is hanging out here was seven but wait we've got one electron leftover that's extra electron that women are negative charge and that extra electron said right here now the oxygen on the outside to for 6 8 the oxygen that's double bonded to for 6 8 and everyone's happy now the normal mining status quo a carbon is for carbon to have for bonds and oxygen to have to bonds to lone pairs min to redraw the structure in the more classic form in which a double a pair of electrons is replaced with the bond Mikesell so this CH bond here that line means a pair of electrons this is by no means a pair of electrons this line means a pair of electrons and withdraw the carbon and I'm on the right this line means a pair of electrons between the two carbon atoms single bond to this oxygen double onto this oxygen to extra pairs of electrons their shirt 8 to bonds to lone pairs and then this one had one bond and a total of three pairs about shared electrons K so this carbon atom has for bonds as expected this carbon atom has for bonds is expected by the amounts they re this oxygen atom has to bonds to lone pairs is expected by the events they repeat this oxygens kind of unusual last oxygen does indeed have an octet but it does it in a non-standard way it does it by having a total of one to 3d for by six electrons that are part of a bond and then a seventh electron if you think about it sharing electrons with carbon so total for bookkeeping purposes it has seven palance electrons K oxygen normally has only six palance electrons so this oxygen atom actually hasn't extra electron so we give it a formal charge at -1 formal charges are ways to keep track of where any excess or deficiency of electrons is in the molecule by assigning it to a specific Adam and either has a excess where deficiency I love electrons so now we have a lewis structure for the carbonate I am