Acids and Bases: Buffer Calculation - Past Paper Exam Question Walkthrough｜AQA A Level Chemistry

[@easymodeexams33]

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[@afique1007]

you are literally saving me rn

[@Alandd71]

Absolute fucking legendddd!!!! Exams start in 25 days and I'm finally starting to understand this

[@easymodeexams33]

💪💪💪

[@Gurpandslurp]

I got 8 hours to lock in

[@SnellyDoggy]

@@Gurpandslurpeasy bro just cover acid and bases and thermodynamics. usually they are a huge chunk of marks thats what im doing rn

[@sheggs5499]

💀

[@sohani4376]

@@Gurpandslurpi’m cooked

[@lyssiesworldd8453]

Literally carrying me through my A-Levels 🎉 Please make some on Organic chemistry

[@easymodeexams33]

I've got quite a few organic videos on my channel already on organic synthesis, alkenes, NMR, benzene, and various mechanisms, etc., hopefully they're helpful. More to come!

[@unknownsunbeast480]

Bro I went from not being able to do this to almost getting full marks all the time

[@easymodeexams33]

Nice!

[@anotherdayofpreventingtrav8513]

Omg what a life saver !!!!!❤❤❤❤❤❤ (Exam starts in about an hour)

[@easymodeexams33]

Good luck :)

[@royavajdi_]

So real man 😂 good luck. We got this

[@zarakhan6903]

legendddd! thank you so much. i recommended this video to all of my friends

[@easymodeexams33]

thanks :) good luck Zara

[@elestrello6564]

chat are we cooked for paper 1 tmr

[@hbanksy]

Thanks for this mate, this one thing was just not getting into my head for the longest time

[@easymodeexams33]

no worries, good luck!

[@iknowimwrongbut4491]

yess, needed this. Thank u so much your vids are great

[@easymodeexams33]

Appreciate the kind words and support :)

[@angellll7272]

Thank you soo much! The way you explained the theory behind it, has really helped me to understand these calculations a lot better :)

[@easymodeexams33]

awesome! good luck

[@ravjayakodi2746]

@ 14:00 do you still have to show the cancelling out of the volumes ?

[@rutheshete2400]

u are a star, I was so confused; I got some hint now ,Thanks

[@easymodeexams33]

no worries :)

[@Beautifulday1231r]

But if the volume doesn't remain constant would I be able to use just the ratio of moles Sir, or is it best to convert

[@easymodeexams33]

What exactly do you mean by use the ratio of moles? I don't quite understand

[@Beautifulday1231r]

@@easymodeexams33 so I just find number moles without converting back to concentration

[@Beautifulday1231r]

@@easymodeexams33 so just moles of acid over moles of salt

[@Beautifulday1231r]

However this doesn’t apply to every Q right? Because I seem to not get right answer when I didn’t convert back to the neconcentration and plug it into equation

[@easymodeexams33]

@Beautifulday1231r nah you need concentration every time, unless the volume within 'c=n/v' in the top and bottom of the fraction are equal and cancel, leaving "c=n", allowing you to use either c or n. The Ka expression is all about concentrations so use concentrations, NOT MOLES, if you're unsure if the volumes can be cancelled.

[@moa7651]

super helpful!

[@gaanavmanyam9214]

If this question was with diprotic base, would you times concentration by X2 ? Then use the moles of OH to workout out the new number of moles fo HA and A- .

[@easymodeexams33]

That is beyond the A-level spec mate, so don't worry about it :) If you're genuinely interested and really want to know, here's a video from another channel explaining it: kzbin.info/www/bejne/q5jCdnyKodutm6s&ab_channel=JacobStewart

[@gaanavmanyam9214]

@@easymodeexams33 Oh ok, thanks for the clarification.

[@easymodeexams33]

I want to make it clear that this method applies to all buffer calculations that involve adding a small amount of acid or alkali solution (which is most cases). The method is slightly different when you're adding a solid base (e.g., NaOH) to partially neutralise the weak acid. If I get some time I can make a exam question walkthrough on this too.

[@parisasafdari13]

Please make this video🙏🏼, i was just about to ask why on an exam question they hadn’t added the moles of the base, and only subtracted one part. ( for ref paper 1 2022 question 4.5)

[@easymodeexams33]

@@parisasafdari13 I will add this to my list and get to it if possible 😄

[@lilac_turnip4767]

@@parisasafdari13what was the answer x

[@easymodeexams33]

@@parisasafdari13 Sorry Parisa but I haven't had time at all to make this video. Please check out page 5-7 of this pdf from chemrevise, it should help you out :) chemrevise.files.wordpress.com/2022/01/1.12-revision-guide-acid-base-equilibria-aqa.pdf

[@parisasafdari13]

@@easymodeexams33 thank you

[@itsyogirlsavanna6640]

12:01 if you had HCL dissociating, would the H+ value be added to the ch3coo- valvue

[@AdamQ22]

If you still need it, no it would be added to ch3cooh and will be decreased from ch3coo

[@JojonaKimiyona]

UR A LEGEND OMDS THIS SAVED ME

[@lilac_turnip4767]

Why is the moles being used in the final equations instead of the concentrations? Aren’t we meant to use concentration because of the square brackets in the KA formula? Thanks x

[@muchayevamadzimure8895]

you can use either moles or concentration im pretty sure based off the question. if you use concentration you will still get the same pH as with moles - it just depends on what the question gives you

[@LilMiro]

If you write it out, the concentrations cancel out since they’re on the top and bottom of the division

[@alexbesimming5835]

Would we be able to have a video regarding amines and amides, AQA If possible. Tysm for this vid 💓

[@easymodeexams33]

Yeah bro I got u, I remember your channel name and don't worry, your amine video request is still on my list, working through the list still but it's kinda long lol. expect an amine vid soon :)

[@easymodeexams33]

lol I just checked the list and got your amino acid request mixed up with amines. Which would you prefer first?

[@pinkiepiek1d808]

Your vids r the best thank u so so much😊

[@LennyGGnoRE]

bro where was this when i needed it a week ago

[@easymodeexams33]

lol

[@Fatma-zahra212]

When you add naoh the ph must increase but due to the buffer it will resist the change so shouldnt the ph dectease and become more acidic.. my ph decreased from 4.43 to 4.35

[@aishahsharjil7310]

please make for amine and amides

[@easymodeexams33]

fosho, got the amine topic as requested video already, so expect vid on it soon :)

[@alexreeves4503]

Thankyou!!

[@easymodeexams33]

no worries :) good luck

[@user-su6js9po4l]

thats why hes the goat the goaaaaaatt

[@easymodeexams33]

😂 thanks

[@rayzino3338]

🔥

[@MasokaLeandre]

thanks boss

[@MK-sh7ol]

naa cuz why can't our school teachers be this good :( My Chemistry teacher just chucked a bunch of equations at us and that's about it, so damn frustrating. literally every class he teachers has complained about him but unfortunately nothing has been done!

[@easymodeexams33]

I've had teachers like this too, long and frustrating

[@muhammadanas7791]

The pH value is a long ass answer indeed

[@easymodeexams33]

lol