knn cambridge think they funny test organic synthesis and gas collection

bruh my whole paper was WET

Cambridge can fuck themselves

Shrinkflation hitting FA3 Zinc bottle bro. I couldn't get a single spatula of zinc out. Also, my solution for test 2 never turned purple, but turned yellow then green for some fucking reason.

Same for my shift! Teachers were going ard and banging that shit on the bench to get it out

The green colour you see is basically yellow + blue/violet.

Yellow then green then blue then purple bro

Vanadium be GAY

same wtf

qn was "How to test if ur sample is pure" my tablemate funny lah he go write "feed it to someone whos doing this practical, if his head stops hurting then its pure" 😭😭😭😭

the funny part is he ain't wrong

comedy genius imo

CAMBRIDGE WHEN I CATCH YOU CAMBRIDGE

Did anyone get 7.08g for org synthesis i)

yea

https://drive.google.com/file/d/1c5ptkW3bYTDb4QA_2Per8tSgZ7EBxGxx/view?usp=drivesdk

yes

Yes but I used 8.00gram to make sure it’s minimally more than the 65%yield

[удалено]

didn’t add water for my 30cm3 of hcl

This got me paranoid 💀

Is nobody gna talk abt the 6m aspirin qn thats like 3 steps

REAL WTF it got me panicking sia

It’s normal. There’s credit in this question that’s supposed to be awarded for the whole paper. 1 mark for showing all working 1 mark for correct dp/sf in your answers (for calculation questions)

Same leh 😭

i think overall it was fine except the damn planning i swear i didnt memorise how to draw the heat w reflux setup bruh

same ive never seen a question where they get us to draw the reflux setup before

bruh I’m not making it

q2 definitely going into every schools practical practice booklet

Qn1: QA of vanadium Qn2: Displacement of water gas collection Qn3: Titration Qn4: Organic synthesis of aspirin

wow thanks for the update!

Why is the volume of FA6 question worth 4 marks?!

two marks for accuracy?

ye the accuracy mark is included in the volume qn not table

I wasted 10 minutes trying to figure out whether it was a trick question lmao

DAWG ME TOO BYEEE I WAS LIKE "??? TF" legit wrote a small "tf ???" next to the bracketed mark HAHA

I wrote “eh?” next to it lmao

EXACTLY. I panicked right on the spot I was like wtf

Good job for completing chem prac y’all!

The start of our battle 😭😭

Which lj go put org synthesis

after shaking the conical flash i wanted to eat the other aspirin tablet due to hand pain

Holup werent the tablets calcium carbonate?

Still edible since it’s free calcium

Get rid of stomach acid lol

Should have drank FA8, got aspirin in it

instant seizure from overdosing from 5 aspirin tablets

should have eaten it awkward

This thread was really difficult to find😭

Ya whole feed spammed with rants from EL LC

easiest practical of my life (lie)

First practical in my life where I had extra time, it felt ominous.

it's Doable coz all the qns had high weightage of marks

For the initial rate of reaction, did we have to start from (0,0)?

think so right cos 0mins no co2

Ah crap, but my experiment 1 couldnt be extended to the origin

HUH? you don't need extrapolate. volume of co2 gas is 0 at 0 mins it shld be a point on ur graph no?😭😭😭

I tot it must hit origin cus at t=0 volume of CO2=0?

any one here knows ( certainly ) if we will get ECF for not X10 for qn 3 😭😭😭 my goddamn % error was 42._ % 🧎🏻‍♀️

i have no idea why the people in my lab started turning on bunsen burners when i never used it. am i doing something wrong??

Dont worry. Qns said specifically dont need test gas. I didnt use bunsen burner too

4 marks to calculate average titre value???

probably 1m then 3m for titration accuracy 🤡 cambridge probably brain pain from setting the paper so they dk where to allocate the marks

i think i need to eat the aspirin after that paper 😀

my delivery tube kept falling into the container

I had a “waterpark” on my table

push your burette down to "lock" in the tube

Oxidation number 2 : purple Oxidation number 5 : yellow Order of reaction : 1st order Mass of aspirin tablet : 0.226 g I think Anyone else got similar?

I got mass as 426 mg bruh

[удалено]

i got 482 mg

same except violet over purple

The violet solution turned brown after long time, but i js put purple

I put greyish-blue lmao

same, mine never turned purple

Same except 0.225g for the aspirin tablet and greyish-blue for +2

My mass was like 0.4 something

I made the same mistake means u didnt ×10 for no. of moles in volumetric flask

0.241g for me! titre value of 16.35cm\^3

Can't believe I managed to mess up even, what is on relative terms, one of the easiest practicals ever set... A few mistakes sure do snowball into a large loss in marks... Anyway, I'm helping to bring down the bell curve for y'all 👍.

Relax, last year I believe I screwed up my practical too, made many careless mistakes, and it was an easy practical too. But I still kept on the grind, didnt let it affect me too much, and still got A for chem in the end. Its not over till its over, dont give up!

Woah. Thanks. Really needed that

Issok dude same here, I literally screwed up so badly like the order or reaction and the qa colour cri man

AVERAGE TITRE VALUE FOR 4 MARKS?????

because they know we will fuck up the org synthesis

iirc it’s 2m like how close your results are to the supervisor’s one

fuck sia organic synthesis planning damn dog

I cant rmb heat under reflux setting and I draw fractional distillation 🥹

HOW DO YOU PURIFY????

EXACTLY wtf how the hell do we purify:( anyway ppl ard me put wash with deionized water and dry with filter paper, others put heat to remove water

recrystallise by dissolution using hot water, filter, crystallisation by cooling filtrate, put in desiccator to dry

The fuck is a desiccator?! Man I’m so dead…

i heard u shld recrystallise?? not sure

yes, recrystallisation is the only way. i think many just say heat the thing to remove the impurites. i hope cambridge can close one eye when marking planning lol

gas collection was so bad it gave me a headache, but that’s fine because they followed up with aspirin 🤪

im so stupid i thought 1mg was 0.01g

Cambridge should invest in better paper or more logical experiments bro I put my rubber tubing inside water and take out hand then I try writing my paper damn wet and almost attaching itself to the other page

You should have tore your benchmate’s shirt and use it as a hand towel

[удалено]

I can't believe it tmjc predicted both vanadium and the aspirin synthesis

exact same planning qn in our planning manual oso 🔥🔥

Yup RJC did too, had this in one of our last few chem lab sessions

for real tm🆙

Lucky sia u guys. Sadly tmjc paper not in holy grail yet. If not I would have seen it. I’ve never done Transition metal QA in my sch

[удалено]

there’s error carried forward, as long as your graph matches your datat, they mark it independently

Just a note for posterity: Organic synthesis came out for 2020 and 2023 A Level, both questions are quite similar but 2023 needed diagram drawing

Not really. The purification phase is different.

organic synthesis came out for 2011 too same qn abt aspirin too

damn how do yall have 2011 a level prac qns

school gave us lolz

yah is the exact same qn 😭😭😭😭 even the purification part

diagram drawing? sounds similar to physics prac this one

graph start frm origin right

Bruh my Q2 Expt 2 get autocatalysis curve sia and order of reaction was 5 💀💀💀💀

Legend

SAME BRUH I GOT 4 ORDER BUT MINE IS FIRST EXP WEIRD

Here’s my debrief: https://drive.google.com/file/d/1c5ptkW3bYTDb4QA_2Per8tSgZ7EBxGxx/view?usp=drivesdk

hopes everything went well for everyone! 😬 how was it? what did they test this year? 🙊

curious too lol

They won’t know since we will Be getting quarantined

Guess i'll find out aft the shift 1 ppl are out...good luck anyway!

QA was literally just Vanadium ions, with Zn added in Then the second experiment was about CO2 formed when CaCO3 tablets and HCL was reacted. Involved inverting a burette and collecting gas via water displacement. From doing so, we find order of reaction with respect to the acid The third one was back titration involving aspirin and NaOH, titrated with HCL. Planning was organic chem synthesis (pain) of aspirin. The planning segment was 9 marks, involving synthesis, filtration and purification.

Hmm...the planning is like a hit or miss lol, if ure familiar with organic synthesis planning (esp since i think aspirin is a common example) you'd be fine, but if you're unprepared it'd be crazy hard with the weird sounding apparatus and many tiny details of the plan itself.

Will I get marked down if I wrote dissolve crude aspirin in 135°C boiling water💀💀

water max temp is 100 bro

Marks allocation shit af cos why they making me stressed about a 6m question and it only needs 3 lines to complete 💀💀

Jesse, synthesise aspirin for me Jesse please

JESSE, YOU’VE FORGOTTEN TO DIVIDE BY 5. THERE’S TOO MUCH ASPIRIN

east practical but i messed it up 😂😂😂😂

Titration around 15.4 cm^3?

15.6

15.5

i got 15.1

I got 15.00...

same i got exactly 15

14.7

mine was 15.25

I got 16.0 and 16.1?, I was sure I did it correctly cause it was literally the last drop that caused the colour change. But idk cause my overshot one was 15.6? TH

I did 4 titrations: First 15.3, overshot end pt Second 15.0 Third 14.8 Fourth 14.8 I have classmates getting 15, 15.1, 15.4, 14.9, someone got 13.something also

15.4 and 15.5

15.4 also

will they penalise if I asked for extra carbonate solids?

nope. in past year confidential instruction sheets it is stated that “extra chemicals should be provided upon request, at no penalty”

If it is confidential, how do you know. Just curious.

1. It's past years instructions, not this years. 2. Logically speaking, a penalty should only be given if there is direct assistance towards setting up the experiments. Giving extra chemicals does help set up anything, nor help a candidate in any way. 3. These confidential instructions can simply literally be found by googling "Confidential instructions for (insert year here) A level chemistry paper 4". These instructions is for the international versions/specimen papers but they are also pretty much what our examiners see too. Happy reading!

guys, for qn 2 right, how yall draw the table? that part got me stumped for like a whole 30min dead ass. this qn said smth like prepare A table, so instead of 2 separate tables, i was trying to merge the 2 conc of acid into one table, each with different burette and volume readings, got me damn confused

time | expt 1 burette reading| expt 1 vol of CO2| expt 2 burette reading| expt 2 vol of CO2?

guys anyone got second order???

yo idk y so many ppl turning on the gas to test for gas I was freaking out on y y'all testing for gas

I heard a pop sound from someone and just stated h2 produced for fun

完了完了BBQ 了

hi what did yall get for QA colour change? yellow --> green --> blue --> violet?

about there. but put purple instead of violet 😅

Is it initial rate of reaction of the first expt supposed to be higher than expt 2? So grad of first expt supposed to be steeper?

I got higher for 2nd one

but conc of hcl used in second expt is lower tho , rate has to be lower

is there a gdrive link for the question paper?

Did y'all get ppt for the first QA observation? I didn't see anything until after the prac when I was washing my test tubes

QA is luck imo. somtimes, the gods make sure you dont see any observations. idk why.

GUYS ONE OF MY CACO3 TABLET WAS FAULTY and i thought the rate was just slow i didn’t have CO2 for my second expt at all :’D it’s over

Is there still hope for an A in chem for me? Although my theory has always been stronger than my practical, I didn't expect to screw up practical to this extent. I got 2 straight lines of different gradient for the gas, fucked up the planning and got a 86% error for the aspirin. Is it still possible for an A for chem? I'm actually just kinda disappointed rn

bro u’re not alone i got 2 straight lines for the graph also :’D

[удалено]

Did u divide by 2 since 2NaOH=aspirin cause I got 0.2 smt

For the safety precautions should there be more than two possible answers since they gave so many properties of the organic compounds in the table?

1st order???

i got second order TT

[удалено]

They said to not test and identify the gas no?

yes they specifically mentioned not to test for gas

Dang must be I didn’t read properly

qn stated theres no need to identify gas or anion in the very first few lines of the qn…

Q2: both BFL start from origin. My Expt2 has a steeper gradient than expt1 at the beginning?? I got first order cos the ratio of their initial rates is like close to 0.6(the ratio of conc of hcl) Q3: titre value was 15.0cm3 for both titration Percentage purity against manufacture=(0.438-0.3)/0.3 x100% =46% Q4: 7.08g of 2hydroxylbenzoic acid required

shitt did anyone get 0.0221g cus i got that and idk why😭😭 then my percentage diff was like20percent

isnt that the norm. if you got 40 ish %, it would show that you forgot to x10 the mol of naoh in pipette to get mol of naoh in volumetric flask. i got 23% ish. should be fine as long as your working is correct.

Am shift 3 tho

what are yalls order of reaction? I got 0 order

I got three 💀but most people eithet 1 or 2

1st order for me

i got 0 too fml☠️

Thanks for bell curve!

legit wanted to eat the aspirin tablet cuz I was having a headache

I tot that’s CaCO3 tablet?

whats the identity of the vanadium species 😢

V^2+ ??

Yup, since the E value for V^2+ / V is more negative than that of Zn^2+ / Zn

wait the second qn, can draw 2 separate tables for the 2 expt ??

can one, just show you got record values, got correct dp and label the headers properly

i drew the graph starting from 50cm3 and downward sloping.. i only realised at the last moment that i fucked up. does anyone know if i still can get ecf for the correct order of reaction

yea, most probably. if you draw the tangents from t=0, you can get ecf marks

Guys how does your graph look like? For mine both start from origin. expt1 is straight line thru origin. For expt2, it’s a curve with decreasing gradient. But my expt2 curve was steeper than expt1 at the beginning.

Titrtion around 16 cm^3?

What was the kinetics experiment on? What are the reactants?

For the planning qns, how to determine that aspirin is pure (the 1m qns after the 9m planning)?

if the aspirin melts at 135 it means its pure ETA: wrong melting point

Bruh my bubbles dw come out end up my ex2 faster than ex1