CHEMISTRY PAPER 3 DOUBTSS!!

[Zaki ali asghar]

Mine was 54.6 i wrote the same improvement as you kept thinking about the lid thing in the last minutes ended up writing sth about loss of Co2 which is wrong

 

[Zaki ali asghar]

what about the maximum error for volumetric flask?

 

[sarmadimran]

what about the maximum error for volumetric flask?

0.04

 

[sarmadimran]

Mine was 54.6 i wrote the same improvement as you kept thinking about the lid thing in the last minutes ended up writing sth about loss of Co2 which is wrong

Ohh..we were given 20min extra due to gas problem so we had a lot of time for this question

 

[chichibung]

Which variant are you talking about?

 

[sarmadimran]

Which variant are you talking about?

33

 

[sarmadimran]

What was the anion in question 2?..I wrote unknown and its wrong

 

[Cherry lava]

What was the anion in question 2?..I wrote unknown and its wrong

Co3
Carbonate

 

[sarmadimran]

Co3
Carbonate

But there was no effervescence I repeated it 2-3 times

 

[Zaki ali asghar]

CO32-,there was slight effervescence.

 

[Zaki ali asghar]

I repeated it and covered the top of test tube with thumb and then i saw bubbles and pressure was building up.

 

[sarmadimran]

I repeated it and covered the top of test tube with thumb and then i saw bubbles and pressure was building up.

Ohh and how did u calculate percentage purity...
1) 0.05xtitre/1000
2) answer(1)x 2
3) answer(2)x10x84
4) answer3/mass x 100
Is it correct?

 

[Zaki ali asghar]

I am not sure about third because i might have messed up in that,rest is same as mine.

 

[Zaki ali asghar]

what did you assume about the impurities?

 

[sarmadimran]

I am not sure about third because i might have messed up in that,rest is same as mine.

Many students messed up we had to multiply by 10 I'm pretty sure because we used 25cm3 and the volume in flask was 250cm3

 

[sarmadimran]

what did you assume about the impurities?

Impurities does not react with sulphuric acid

 

[Zaki ali asghar]

what volume did we have to use?

 

[sarmadimran]

what volume did we have to use?

Which volume?

 

[Zaki ali asghar]

Which volume?

i think i multiplied it by 4 the no of moles,dammit.Took volume as 250 instead.

 

[sarmadimran]

i think i multiplied it by 4 the no of moles,dammit.Took volume as 250 instead.[/QUOTE

Ohh