Just thought I'd drop a heads up for any students watching this in the future! Having sat my Paper 1, I can confirm that this year they did decide to ask you to describe electrospray ionisation! I thought it had been removed from the spec, and as I was watching this video and you seemed to agree that we wouldn't need it Mr Rintoul, I didn't bother to look at it. Turns out I had to rely on my knowledge from my year 12 class to try and remember haha. In case anyone thought it was, this is in no way supposed to be a hateful comment blaming you or anything Rintoul, I just thought I'd mention it in case anyone from the future (kinda weird concept) finds this useful :) [Also please excuse my wording if it's clunky, I'm not used to writing comments haha. Probably no-one will see this anyway xD] Edit: So I was just brought back here around a year and a half later because somebody commented on the post, and I didn't expect to see so many likes - I'm glad people found my comment useful! And of course, it's awesome to see that people are still using Mr Rintoul's videos! These are certainly strange times - good luck with everything and make sure to also take care of yourselves. Stay safe :)
Hey person from the future here... just started year 12 we just covered this in class and my teacher said that we wouldn't need to know it either. Thanks for the heads up!
You sir are a LEGEND. I was wondering where this video was, as I have my mocks after Christmas. Thanks so much on behalf of all of your subscribers. :)
Hey Hitsu, I absolutely love Eliot's videos too :-) I'd also recommend this channel, Study Mind, who are launching a free AQA A-level Chemistry course on RU-vid. Good luck with exams all! ru-vid.com/show-UCzFXGNbYzfgXApJjlVqV_eg
oh you legend, thank you so much for this video, for a year my teachers have been so confused with what type of mass spec goes with the new specification THANK YOUUU
Wow great timing! Going to start revising AS in a few days and for chemistry will definitely be watching your videos before I revise each topic myself because you make everything so much easier! Thanks!
you're an actual legend i was taught this is class today and understood none of it now i pretty much get it thank you so much stg your videos are so useful
thank you so much, I am just wondering how come i didnt come across to any of your videos before, you are doing great job thanks once again and God bless you
Your videos really really help me understand these topics. I have a lot of trouble with titrations, it would be amazing if you made a video to try and explain it!
Hey Lucie, I absolutely love Eliot's videos too :-) I'd also recommend this channel, Study Mind, who are launching a free AQA A-level Chemistry course on RU-vid. Good luck with exams all! ru-vid.com/show-UCzFXGNbYzfgXApJjlVqV_eg
hi your videos are really helpful ! i'd like to ask why some of your videos are not on the channel? things like aromatic chemistry , it says you have a playlist for them but there's no videos ? is there any chance you could make videos on these topics thank you so much !
I honestly cannot possibly thank you enough. I'm in As with cies in a week and i wanted to revise my topics and i had not compiled any notes and this just saved my life! I have a question though. The last question that you solved, what if i take the variable x to be the assumed percentage of Mg-26 rather than Mg-24 that would be considered correct too, right because my answers for that solution came up to be 35% and 55% ie completely diff than yours
I have a question... In the mass spec of propane when fragmented the greatest peak/mr should be @ 43 right? Due to it being an ion and then the peak @ 44 should be due to C-13... But in the AQA student guide it says that the mr of propane is 44m/z
Electrospray ionisation is essentially ejecting a dispersion of a high volatile solvent with high polarity to trigger off that charge when atoms knock into them in the chamber (a source of protons). What I don’t get is when injecting high energy electrons from the electron gun. why does it have to be as some say bombarded with the gaseous substance? What is the function of the gaseous substance for?
Can you please finish the amount of substances chapter? I'm really struggling with it and your two videos did help a lot but there is still a massive chunk left. Btw thank you so much for the videos your content is amazing 👍🏻
I believe the mass of the different isotopes is calculated by the time it took the ions to reach the detector as the ions with bigger mass will have a lower velocity (KE=1/2mv^2) as long as their KE is the same. So using the constant KE (applied to all ions) and velocity which can be calculated from the distance of the ion drift segment and the time of flight, their relative masses can be found.
thank you! Please can you do a video on comparing the two types of ionization because that was something that AQA added to the spec very last minute and we didn't get taught in detail
As far as I'm aware, you don't need to be able to compare the two different types of ionisation. Unless something changes in the future, the mark schemes that I have seen have included both types of ionisation as answers when the question asks for a description of the ionisation process.
How are we meant to know whether the higher mass isotopes are due to molecules or whether that just the mass of each atom of the element? Can someone pls help me cause I’m kind of confused xx 12:53
Hi, I love our videos!! I'm currently studying A-Level Chemistry, Psychology, Business and Sociology. I intend to do a science type course at university and I was wondering with these subjects, what sort of field I could get into? Or am I not limited to courses with just chemistry?
Uh idk what u mean ngl but I watch snaprevise aswell as some of their chem vids are free If u want past paper questions or something just google Mass spectrometry Alevel exam questions with your exam board
I know you said you weren't covering fragmentation, but I'm resitting the legacy paper for CHEM4 so still covering that side of things. Would I be correct in assuming that if you were covering fragmentation, you would have included the radical on the [CH3CH2OH]+ at 15:21 ? Thank you!
Electrospray is used for larger molecules to prevent fragmentation and is called soft ionisation. It could potentially come up as a q so I wouldn’t ignore it.
Whilst that may be true (and I don't claim to be an expert so don't know without looking it up), what you've said is not true for the A-Level in the sense that they would not be questioning on something that isn't required. The specification says: The principles of a simple time of flight (TOF) mass spectrometer, limited to ionisation... The specification used to specifically use the phrase "electrospray ionisation" but this was changed a couple of years back.
Went to chem teachers’ presentation at Liverpool University. NMR specialist Dr Cate Cropper discussed this. Whilst they may not need to know protonation it could be asked in a S and C capacity when looking at proteins. Why wouldn’t hard ionisation be used? It’s in the AAQ student note supplement that came out after the “new spec” was released. filestore.aqa.org.uk/resources/chemistry/AQA-7404-7405-SG-TOFMS.PDF
@@wendywinnardChemistry I'm not suggesting that this isn't real, rather I'm saying that the specification just mentions ionisation and as such, I think it would be very unfair of them to structure a question that focused on only the electrospray version. I suspect, as I think has come up, that they would be more likely to ask students to describe the ionisation stage and would accept either form. This was the comment they posted back in 2016: www.aqa.org.uk/news/changes-to-as-and-a-level-chemistry-specifications-march-2016
Am honoured to get a reply Mr Rintoul and have gone up in my students’ estimation because you’ve replied! In any case they’re all motivated to study both types! Thank you for your fantastic videos. May there be many more.
Sir how did u assume the scale cant we assume it as 20 40 60 80 and we go on till it ends can we do that because i was having a confusion at these AND PLEASE TELL ME SIR ARE THESE VIDEOS RELEVANT FOR GCSE????
Typically the equation for Ar (relative atomic mass) = mass of one atom/ 1/12 of C12 I thought C12 was always 100? But aside that thank you for this video!
