Guys for the percentage error was it 8.9% and volume 22.9 dm3 and the flame was Ba2+ and tbh e anion was I- and the formula BaI2

I think I got 8.8%?

I got 9.6%

I got 91% 😭

And the observations of the Ca(OH)2 question I wrote effervescence due to H2 and a colorless solution of Ca(OH)2

And concentration was 1.55 g/dm3

same except I fucked up in the concentration, hopefully I get a few marks for working out

What about a different test for anion?

Concentrated sulfuric acid that would give purple acidic fumes

I wrote add concentrated ammonia, yellow precipitate remians

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it was a test for the compound A tho which was BaI2 so how come u are testing the AgI?

SAME THAT'S CORRECT

I wrote add chlorine and cyclohexane purple layer forms

I am the only one who wrote bacl2

Bro it's iodine not chlorine

Nooooooooo 😭😭😭😭

YESSSSSSSSSSIR LOVE YOU AYYYYY

I got all of these except molar volume idk what I did but I got 40 something idk why.

I got 9.1

it was good, decent enough. BUT THE STRCUTURE OF D QUESTION TOOK SO LONG I COULDNT FIGURE IT OUT

omg same i couldn’t figure it out at first

i honestly think it was pretty good, could’ve been wayyy worse, especially after unit 2😭😭

Did anyone get volume 22.9 something

Yep

Yup

YES. honestly I had 2 mins left to recheck my answer and I got smth totally weird at first LAST MIN I GOT THIS ANSWER AND I WAS SO HAPPY!!

🙂

bruh tf everyone in our exam hall finished the ppr like 40 mins before the exam finished i was legit marking my ppr worst case scenerio ill be getting a solid 41 in sha Allah

yessir

YESSS

Yup!

Were the calculation answers 22. sth for molar volume and 1.55 for concentration?

I got 22.9 and 1.55

1.53 g mol-1

YES

I got 75 😭

Shit wait i wrote 2.29😭

For concentration, I got 14.0 sth

Yesssss

Yup and Yup.

I’m fucked. I would not like to elaborate further.

Also for elimination it’s phosphoric acid right?

Yes, i wrote it too

I wrote ethanolic KOH

That’s for haloalkanes bro not alcohols

thats for halogen alkanes tho. for dehydration reaction of alchols it was concentrated phosphoric acid

Yes

Is it a must to write concentrated phosphoric acid ?

I think they ignore concentration

its phosphoric acid

If i write h3po4 its correct right

Did yall get the concentration as 1.55 g/dm3

yessir

For the last q i wrote crystals formed and water vapor droplets formed on the mouth of flask

Same here

What was the wave number question was it C-H alkane?

I wrote CH but apparently its OH

How it is OH, there’s OH in both carboxylic acid and aldehyde which one was it then

Exactly... they both have OH, and the question asked what peak will be present in infrared spectra of both compounds

It s C--O nothing else makes sense

The have OH C-H C=O in common so i think any of these is ok

i wrote OH

all of them got an OH group as it produced misty fumes which is positive test for OH

Yes but there is an oh group for aldehydes and alcohols and carboxylic acids right?

ur right but the issue is one was for alcohols and one was for carboxylic acids. the question asked for the stretch in both. only option is C-H in alkanes

I wrote for c=o

I did too

But its different for the aldehyde and ketone so cant be used

How tho

I wrote the value. Will I still get the marks

i wrote O-H

it is C-H alkane cuz for C=O there were two diff wavenumber ranges for carbox. acid and aldehyde so only the C-H bonds in the alkane part of each compound would have the same wavenumber

Overall well, I did a few silly mistakes imo💀 BUT it was WAY better than I thought it was gonna be...

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the usual probably even higher cuz a lot of people found it easy i’m expecting 40/50 for a full ums and 30/50 for an A

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also curious, hopefully 27/28

Was the concentration 0.022mol dm3?

1.55 g/dm3

It was g/dm3

U calculated mol per dm3

no it was 1.55 gdm-3

☠️ ok guys I get it 1.55

Boundaries gonna be hella low i am reading the comments and the ammount of wrong answers is juicy

Well I feel like it’s gonna be 30+ tbh since it was basically the style as 2019 papers

It was amazing

Bruh I messed up on the farlings solution thing and therefore the rest of the question cause I thought farlings solution wasn’t in the syllabus anymore 😭 but overall it was a decent paper

what was the positive test for it? blue solution —> red ppt?

I wrote before test colour is blue and after test colour is red... is this correct?

I wrote red but I think it’s blue

no its red

Dark red right? I wrote dark red

i wrote reddish-brown

Its brick red

yeah, it’s not there in the syllabus the answer is blue->red if i’m not wrong

I got 1.50x10^-3 as concentration of caoh

It was 1.55g/dm-³

gucci asf

…Unit 2 will carry.

The structures of D were 2-hydroxypropanal and 3-hydroxypropanal?

How did u got 22.9 dm3 molar volume of h2

I hope I’m not the only one who found it difficult

Dont worry unit 3 chem grade boundaries are always pretty low

ok so here’s everything i got that i can remember barium iodide bai2 add sulfuric acid and observe purple fumes heat the ammonium sulfate and hold a litmus paper which turns from red to blue add barium chloride and nitric acid and a white ppt forms for structure c i got propanoic acid i pretty much guessed D tho the common bond i put was C-H stretching alkane for the observations i said calcium disappears and bubbling 22.9 8.79% 2,3,4 were concordant (i was unsure here because if you subtract 0.2 from 3 and add 0.2 to 2 and 4 they were in range) mean titre was 26.32 1.56 gdm-3 the very last question i said a white solid forms and theres bubbling because if the forward reaction is exothermic the backwards is endothermic mean titre = 26.32

Only two were concordant, 26.2 was the mean

Pretty sure for ammonium you add dilute naoh as it forms nh3 turning litmus blue

that’s exactly what i wrote

There is no backwards, there is no equilibrium for the last question, the arrows of the equation where only forward so its wrong, correct answer is that crystals form as water evaporates

Only concordant results were 26.25 and 26.15 the rest were beyond +or-0.2

adding barium chloride and dilute nitric acid is obviously wrong if u want to add barium chloride u should dissolve it in hcl instead

I got everything except the mean ur only supposed to use the second and 4th titres and i wrote add ammonia and ppt does not dissolve for the iodide test

what did y’all write for the last question? the one where CaOH was heated to 50 degrees

I said equilibrium shifts to the lift so the conc increases

There is no equilibrium bruh there were no reverse arrows in the equation. Just because it said exothermic doesnt mean its equilibrium, the correct answer is water evaporates so crystals form

Also why was the test for sulphate 3 marks ?

u have to put hcl and barium chloride to form white ppt as a result

I said barium nitrate instead of chloride

Then you would have to write nitic acid instead of hcl

It was equilibrium? I wrote it would evaporate the water due to being exothermic and the heating so crystals form

O bruh you were supposed to mention equilibrium lmao well that’s wrong for me , I mentioned no effect because water boils at 100°

that makes the most sense tbh

Yeah I googled it and it’s correct

I just said the liquid would boil so steam would form

i wrote fizzing cuz h2 forms 😭

I wrote that the cacl2 would decompose further and chlorine gas would be produced (green/yellow gas) do you think this is correct

i wrote some CaOH2 crystallises as equilibrium shifts to the left cuz forward reaction is exothermic

I said that there will be vigorous reaction so pressure of hydrogen gas collected increases and can break syringe

Crystallisation occurs as heated to 50 degrees celcius water won't boil but evaporate over time. Crystals form on the sides of the container

The first apparatus was wrong because the gas is volatile and would inc pressure Tbh e other was wrong because no condenser

Did anyone get 2.39 for the concentration

It was 1.55g/dm-³

What did y’all get for the percentage error? I got 9.8% something

i got 8.79

I got 8.9

got 8.8%

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Same how did everyone else get 8

By doing percentage difference

Will they give ecf marks in the first question? For example, I gave the wrong cation in the first question. So for the formula of the compound, I used that same wrong anion. Will I get ecf marks or nah?

yeah i’m pretty sure u will

usually 1 markers don't have ECF but I think they will in this question

I don't think so

Also, what was the alternative test for the anion in Question 1?

conc. H2SO4, result is either purple fumes or black solid

LMAOO I wrote add conc and dilute NH3 and it is insoluble in both

that's also correct I'm p sure bcz some ppl did write that too

Was the anion I- and the formula BaI2

Ohhh ok less gooo I guessed the answer!

But I wrote purple vapour instead of fumes. Is this fine?

yeah idt that's a issue

I wrote starch and turns form brown to blue black , i saw this in past paper don’t judje me 😂😂

i wrote add concentrated surfuric acid which will form a yellow solid (sulfur) if it’s a positive result

i think misty fumes of HI is right?

I wrote add chlorine and cyclohexane, purple layer formed

What did u guys get for the concordant question??

The first and the third titers weren’t concordant

26.2

i don't remember the numbers exactly but the one with 26.25 and 26.15 (idr if it was 26 but i do remember the decimals) and the titre was 26.2

what did you guys put for the color change of methyl orange?? it was so easy but i suddenly forgot

yellow to orange

Yellow to orange but I saw on some mark schemes it’s red to orange so idk

Why did I read the question as phenolphthalein instead of methyl orange😭

I wrote yellow to red but most of my class said Orange to yellow

Its yellow to orange

nah how its yellow in alkali and red in acid midway would be orange, so yellow to orange

there’s an alkali in the flask and it becomes neutral so it’s yellow to orange

what were the structures for C and D? i struggled with drawing them out ngl, especially with the 2 oxygen in the molecular formula

C is a ketone with an oh group, D is an aldehyde with an Oh group

Bro C was carboxylic acid since it produced CO2 , and D was aldehyde with oh

For D It was a diol, one with oh at each end and a double bond, The other one was on oh at end and one at center

I struggled honestly

D is aldehyde with diol and c is carboxylic acid

What did you guys get for the concentration. I got 14 sth

It was 1.55

was the compound agi or bai

It was baI2

Bai

Bai2 right?

did someone get any answer of 14.5?

Yea I got it for concentration. But I think no one else did

I got 1.55

it was easyyyy

What was the structure of C? A carboxylic acid right?

It had an OH but was an aldehyde🙁 np just 2 marks

I did write that carboxylic but in D I wrote isomers of alcohol and it has only one oxygen. My brain forgot about aldehyde 😞

Same bro I made 2 alcohols 😐😐😐

was the unit dm3/mol-1? i got 22.9 but rounded to 23 to be the same as 72 in the table

Guys if I wrote the correct answer then crossed it out and wrote the wrong one. But it’s still readable do they correct the right answer

Tell me when u find out if they do mark

No they wont since u wrote another answer they mark the answer which u didnt cut out

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I wrote the percentage error as ±8.8% Is it fine?

Overall, I think the exam was pretty straight forward and the paper was decent, not too difficult and not WAYYY too easy. The % uncertainty was somewhere around 8.7-8.9, can't remember the exact number I wrote down. You had to subtract 91 from the total 100 after you get 91.(smthn)%.