This video runs through the analytical techniques portion of the AQA Unit 2 spec. It DOES NOT go into huge detail about the process of mass spectrometry and IR spectroscopy as this is not required for the exam!
7:07 for larger alkenes, a quicker way to find out which alkene it is: formula is CnH2n. If n = 1, the relative formula mass would be 14. The question asks for an Mr of 42, so 42/14 = 3 so C3H6
you all probably dont care but does any of you know a method to get back into an instagram account..? I was dumb lost my account password. I would love any tricks you can offer me.
@Mohammed Wells thanks so much for your reply. I got to the site through google and Im waiting for the hacking stuff now. Looks like it's gonna take a while so I will get back to you later with my results.
Thanks for the video, it was really helpful especially the part where you put the exam questions as it helps to apply the knowledge. once again great videos, thank you!
Final recap before the exam - you, good sir, are my new best friend! Many drinks are on me…or they would be if I knew who you were, or where you lived! By the way…has anyone ever told you your voice is...hmm…lovely doesn’t quite hit the spot…but it’s close xD
Please come and be a Teacher at Wilmslow High School... Could definitely do with a Teacher who actually knows their stuff. Thanks so much for these videos, I'm starting this topic tomorrow and this has really helped me to understand beforehand so that I can potentially get ahead of the class. Again, thank you so much!
On the spec it says 'understand the link between aborption of infrared radiation by bonds in CO2, methane and water vapour and global warming' could you explain this please?
thank you man, this was amazing. I just have one question, does it matter what size the peaks are? for example, if one is relatively small does it still count as a "peak"?
Due to the new specification I can't find any updated videos on how the mass spectrometry works for example going into detail about ion drift and the other steps, do you have any recommendations?
Josh Teale Honestly I can't give you a definitive answer, but I would guess that the rest of the molecule being different means that the bond in turn is different. That kind of make sense?
Cheers :) even though I am retaking so I should know all this anyway. May I ask what you do for a living? Secondly will you be doing more videos for Chem 4 & 5 before 10th & 16th of this month?
Not a problem! You may; I'm a Chemistry teacher. And yes, the plan is to get more CHEM4 and CHEM5 videos made this week and and at the weekend (particularly CHEM4 as that exam is first).
The other peaks represent where the molecules in the sample broke apart when going through the mass spectrometer, or lost more than one electron. The biggest z value with a peak is the mass of the molecule in the sample, because it didn't break down.
Just a quick question, if we are reading from the IR the transmittance why when we explain how we deduced our answer we say for example, the presence of C=C bonds in the IR and give the range. Surely what ever is transmitted is not absorbed so that bond isn't present in the structure?
Cygnus I The transmittance tells us what was absorbed. It's like you and a group of your mates walking through a shopping centre. You walk past loads of shops and a couple of your mates disappear into a shop. When you realise, you know that Jon and Miguel have gone and as such, because you know them, you know that there must be an Accessorize because they love that place. By looking at what is transmitted, we know what was absorbed... Does that help at all?!
Josh Teale Thanks again to Connor for answering the question! A reagent is an actual thing that you can add. E.g. you may want to add hydroxide ions for a particular reaction, but you can't just add hydroxide ions, instead you would add sodium hydroxide which provides the ions. Does that make sense?
AQA has recently changed the mass spec stuff for our spec and has added certain things like the kinetic energy of ions; would it be possible to make a video going through this www.aqa.org.uk/news/changes-to-as-and-a-level-chemistry-specifications-march-2016 There's the link relating to the changes, thank you
+Fatima Awow Thank you for highlighting this. I can't tell you how annoyed I am at seeing this. Bloody people at AQA making changes so close to exams. I am furious.
+Fatima Awow I've looked at the link but I'm still confused as to whats different. Is it back to using an electron gun instead of applying a high voltage?
thanks a bunch, the videos are brilliant by the way it's hard to find someone that actually sounds like they know what they are doing without being patronising on youtube :)
xD That wont happen until I watch all of your videos. I have the exam at 13:30 though, so when i wake up will do a past paper and go over what i got wrong.
So that people can watch it before the exam? I could have not posted it at all. But I felt that was a little silly. PS teaching all day means that I'm often quite pushed for time in the evenings.
dude, be a bit more appreciative! This teacher has come home from a hard day's work and produced this video at 9pm for the benefit of you- he doesn't gain everything from it! Besides, I actually find these videos great to watch as a recap just before the exam. Mr Rintoul, thank you very much once again- this isn't something I had thought to revise specifically so this video was particularly useful as a quick last min reminder!
the problem is i watched all your first 10 videos 2-3 time to make sure i understood them then the day before the exam you posted 6. I do not have the time now to watch them all to get a full understanding of them. they are really useful and i thank you for making them.
As I said, I'm busy with other commitments. Half term is a time for me to catch up with my life, and being away from home, I couldn't make any videos. My primary reason for producing these videos was for my own students who will be using them in the future. It just so happens that people randomly found them and have found them useful!
