AQA A-Level Chemistry - TOF Mass Spectrometer

This video looks at the TOF Mass Spectrometer and how to calculate RAM. It does not cover fragmentation in detail.

[@i.buchanan]

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 :)

[@tharushix2983]

Thanks for telling us! I'm learning it now and find it kinda confusing 😂

[@tharushix2983]

I. Buchanan thank you soooo much, I needed that 😊

[@i.buchanan]

@@tharushix2983 You're very welcome! :)

[@dinnythesaurus]

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!

[@i.buchanan]

​@@dinnythesaurus Wow, I'd almost forgotten I even commented here haha, but you are very welcome! Good luck with everything :)

[@malaikaali31]

they go blrululu, the computer goes dilingling !!! i love your lectures so much!!

[@scarlettletter9465]

Nothing like laughing at 5am to 9:07, it really made my day. Thank you immensely for your vids, they really are a treasure

[@joshy-c5389]

it is just hillarious

[@zq1921]

🤣🤣🤣🤣🤣

[@hitsubitsa5039]

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. :)

[@kunaldasani2582]

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 KZbin. Good luck with exams all! kzbin.info/door/zFXGNbYzfgXApJjlVqV_eg

[@mrk.8448]

3 years what happened to u now::)

[@elestrello6564]

5 years.... what happened to u now:))

[@faizasaleem9930]

6 years. What happened to u now :):):):)

[@Abiha...199]

7 whole ass years... What happened to you now :):):):):)

[@domy3470]

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

[@thealooman7894]

Started AQA A level chemistry a couple of days ago. Seeing these videos helps me understand chemistry more.

[@AmbieWolfie]

2x speed for last minute cramming ;) Thank you so much for these videos btw!! :D

[@isaackhan5700]

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!

[@luciecarr7229]

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!

[@kunaldasani2582]

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 KZbin. Good luck with exams all! kzbin.info/door/zFXGNbYzfgXApJjlVqV_eg

[@Mimzy483]

Your videos have saved me. I was on a U in chemistry until I found these 🙏🙏🙏

[@zx12483]

What are you on Now because I'm doing AS and I'm On a U

[@maisamaskari8774]

its been 1 year , what grade did you get?...... just curious

[@beastkaybyt2865]

Maisam Askari I went from a U to a C in AS. Going to do my a level now.

[@Rachel_Tensions]

what grade did you get

[@felipemartinez775]

simps lol

[@N-Kiro]

A- Levels in a month I’m binge watching all videos within a week hopefully 😂 so far they’re very useful

[@ahkamularaf]

same howd it go?

[@Ahmed-kh5xp]

ken kaneki, i like ur profile picture sir :)

[@RollTheReel7]

Love this guy and the work he does to make chemistry easy

[@aksharton7157]

BINGE WATCH TIME...

[@harrietokeefe9658]

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

[@missghani8646]

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

[@onebanghamuud5710]

9:00 Your sound effects are too much LOOL!

[@liamexter]

They are proper A level quality

[@JRRHellFirePhoenix]

This guys gonna save me for the test in 8 hrs

[@anya2753]

thank you so much! i have my AS in a month and this is great for revision

[@aimeeapio8912]

At 28:21, how do you know which m/z to make x or 90-x, because i did 90-x with the 24 mg and got a different answer

[@dorsa5379]

THIS GUY SAVED MY LIFE

[@shakilmpatel]

Thank you This really helped me to thoroughly understand the topic as you also link one thing with other such as the K.E formula thanks

[@landoh3608]

You are the GOAT bro, thank you so much

[@aishah2536]

Your videos are so helpful! Thank you

[@exymath9232]

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

[@anasmohamed7110]

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

[@eleanorgraham6002]

So helpful, thank you! Please can you do a video on carbonyl compounds including esters and acyl chlorides?

[@aleenakochupaliyath8005]

9:07 I had this on 1.5x and omds the water in my mouth went flying

[@ambi4123]

Hie elliot. Thank you so much for this video... This is amazing 👏🏿 👏🏿

[@marsal9994]

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

[@MrERintoul]

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.

[@oOCottonMouthOo]

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 👍🏻

[@tamirahahmed2197]

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 !

[@wendywinnardChemistry]

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.

[@MrERintoul]

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.

[@wendywinnardChemistry]

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

[@MrERintoul]

@@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

[@wendywinnardChemistry]

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.

[@MrERintoul]

@@wendywinnardChemistry haha! Thanks for commenting - I'll be mentioning more detail in the future!

[@khaledragheb6503]

Great Video. Cheers

[@scribbledribble4062]

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?

[@j-behindthecut]

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?

[@puddleduck1405]

what r u doing now

[@j-behindthecut]

@@puddleduck1405 third year pharmacology student 🙏🏽

[@Jazzoo]

@@j-behindthecut holy shit well done

[@forrkarma]

How did you get 3:1 ratio??? i dont understand how to seperated the lines

[@slavmilivojevic5161]

thank you very much, i really appreciate your help

[@StarbuckCaptain]

Are your older videos matched to the new specification? You're great btw :)

[@loucooper2870]

I think he said once that they were.

[@hadis6825]

Yessss omg thank u!!

[@meraki212]

This is so helpful thank you!

[@Fifi-dx2jz]

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

[@mo98jiffy]

Thanks, Im still studying last year's AQA A2 spec, any chance of more videos on them?

[@inspectorlaw]

I am as well dude! I don't know anyone else doing this, how are you finding it? Where are you up to? :)

[@mo98jiffy]

@ruthinlad sorry mate just seen this, yeah I'm finding it easier to recall but still struggling with NMR

[@mariyaj_8872]

You are a god sent 👍

[@Wabeery]

How does the Mass Spectrometer know the mass of the different isotopes to put them into the Mass Spectra against Abundance?

[@VeteranWolfy]

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.

[@jodiejgreen]

Would writing about an electron gun be accepted in the mark scheme?, even though that electrospray ionisation is mainly mentioned

[@theultimateconspiracytheor5778]

Hello sir, on the AQA guide it says something about a negatively charged plate which the ions are attracted to--are we required to know this?

[@MAN59724]

I need this for my Y11 GCSE work!

[@chloe-xr9wj]

Damn this stuff is a level content 😂

[@qusaiothman828]

can you please do one that covers fragmentation in detail ?

[@stephanoparaskeva820]

Do you have a playlist or list of vids specific to edexcel exam board, I like your vids! If you don't do you know any channels like yours that are?

[@yousofalemi2682]

For question 2bi) at 19:40, what could you put as the answer to part 2bii)

[@Fifi-dx2jz]

It doesn't take into account ALL isotopes

[@samiyachoudhrey6880]

thank you sooooooooooo muchhhhh this is so helpful

[@anisahhk2016]

HI sir, does this video still match the aqa specification now? for 2021 A levels? Great video btw!

[@proreviewer6064]

Hi @anisah B yes it does still

[@MastersX99]

Do you have videos for all a level topics or just certain topics

[@1994Ivygirl]

This question is probably really stupid... but how do they get the same kinetic energy if mass affects kinetic energy and some ions may be heavier?

[@shokker2445]

Because the mass of an electron is so much smaller than that of a proton it can be ignored. Bit of a late reply but I know people still watch this

[@sophiamarron1709]

When figuring out RAM would you include molecules of only isotopes?

[@hamzamukhtar502]

Can yo do a video about hydroxy compounds ( Btw great content)

[@T_Bag069]

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????

[@bv1mns]

Taimour Zahid no this is not relevant for gcse!

[@T_Bag069]

@@bv1mns thanks for telling btw are you from pakistan?

[@bv1mns]

Taimour Zahid no I’m not- from North Africa , why

[@acmaahmed2290]

Awesome vid - cheers :-)

[@inspectorlaw]

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!

[@ashd8046]

Is this included in cie as levels chemistry

[@humalohar2075]

Can you please make more videos on the A2 topics.

[@cherrycolagames3187]

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!

[@eshakawol3344]

Hello sir, is that for cie exams???

[@ragtagrey5920]

Does anyone have any websites or yt channels recommendations where there are topical tests for these types of things?

[@NEUROSHOCK123Channel]

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

[@ragtagrey5920]

@@NEUROSHOCK123Channel ooh thank you very much x

[@fizayasin1230]

I didn't get by subtracting what you got 7.2?

[@vemundheier3935]

Our teacher made us whatch this

[@MrERintoul]

Don't sound too disappointed.

[@vemundheier3935]

I’m not it was very helpful 💪

[@troylenny5848]

Hello, can you please explain or name the math technique you used? So I can research and learn to apply it

[@harshsongra1535]

troy lenny calculating mean

[@aavashism]

TYSM!!

[@sunnykim2134]

Is he doing edexcel one or cambridge one??

[@daaragoodluck]

aqa

[@namelesss8226]

is this for 9701?

[@LADfraser]

could you possibly do a video on the full a-level specimen papers so not the AS one. so 7405/1 and 7405/2 please

[@SasukeUchiha-gx6jg]

thanks man great video. !!!!!!

[@chloe-xr9wj]

Need to know both electrospray and electric impact ionisation btw

[@spiralx6249]

That last question would be appalling just as homework. To stick it in an exam... WELL...!

[@retooluvyuhx5569]

THANKYOUUUUUUUUUUU

[@ehgenius9676]

9:06 lol

[@raamkumar9578]

Rintoul realises to much of lecture on maths so says “ANYWAYS”

[@nabila7819]

is 'computer goes dloo loop' a valid answer in exams *sigh*

[@joshy-c5389]

9:07 sadly not

[@farah7665]

Electrospray ionisation came in paper 1 😔

[@C1_YT]

28:22 IM DYINGGG xdDD

[@azibayani3950]

Yo sir u are the best!! Can you plzzzzz make a video on Hnmr and Cnmr? Thank you.

[@MrERintoul]

Azi Bayani I already have!

[@azibayani3950]

E Rintoul ohh sorry, what's the title of the video?

[@azibayani3950]

E Rintoul thanks you!! Found it. 👍

[@aavashism]

i have cie chem p4 today lol

[@matan8074]

Beter then the 3 other videos combined

[@milkshake3117]

26:36 get to the point!

[@axmad_k7]

Okkkkk

[@maisamaskari8774]

Like if u laughed multiple times during the video

[@rawr6984]

Bruh im so lost