For the PV=nRT question, id someone get somewhere around 304? im not sure if thats correct. The answer i got was 3..4 i cant remember the middle number.

Reply 5

carlinhos1999

nah nah it was like 4x10^6 pascals, think about it, it was in a pressurised container and atmospheric pressure is 1x10^3 so it wont be 304.

Reply 6

laney1999

Original post by carlinhos1999

nah nah it was like 4x10^6 pascals, think about it, it was in a pressurised container and atmospheric pressure is 1x10^3 so it wont be 304.

4x10^6 sounds like a familiar thing that i wrote in the exam... i wonder if i got 304 for a different answer...

Reply 7

carlinhos1999

i got 1.85g for the mass of srco3, like 67% for percentage yield, methylpropanoic acid for the last one, rate of reaction like 6x10^-3

Reply 8

carlinhos1999

got the group 2 metal as calcium

Reply 9

KingAuthor

I had 1 minute left in the exam to finish 2 questions so had to rush the equations for NO atmosphere question and yield(?) equation. I think I did them both wrong though lmao I put random equations and just numbers

Reply 10

laney1999

Original post by carlinhos1999

got the group 2 metal as calcium

Same 😀

Reply 11

KingAuthor

for the analytical techniques I got butanoic acid, not methylpentanoic acid
I found a mz+ (or something) and got C3H5+ from my butanoic acid and just registered it as that.
There wasn't an indication that it had a methyl group was there?
I put:
found formula
m/z = 88
molecular mass = 88
(question said final line was due to carbocations)
absorption peaks etc
drew butanoic acid
found a mz+ to help prove it's butanoic acid
and then rush off for a different question for the last minute

Reply 12

X_IDE_sidf

What did you get for the last one. I think it is 2 methyl propanoic acid.

Edit: post hoc Reason:

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Reply 13

carlinhos1999

on the left it said mr peak 43 was a secondary carbocation so it cant be butanoic acid cause that would be a primary carbocation xx

Reply 14

X_IDE_sidf

Original post by carlinhos1999

on the left it said mr peak 43 was a secondary carbocation so it cant be butanoic acid cause that would be a primary carbocation xx

it was the 45 peak but see my previous comment with the actual mass spectra

Reply 15

carlinhos1999

yeah you're right was 45, and judging by graphs it was methyl propanoic acid

Reply 16

elisha.marsh

Original post by laney1999

4x10^6 sounds like a familiar thing that i wrote in the exam... i wonder if i got 304 for a different answer...

I'm pretty sure i got 6.44x10^6 or something similar

Reply 17

Sadiemoose2

Hi just wondering if anybody can remember the topics that came up? Thanks

Reply 18

h3rmit

Original post by carlinhos1999

on the left it said mr peak 43 was a secondary carbocation so it cant be butanoic acid cause that would be a primary carbocation xx

Different fragments can be produced from butanoic acid, and one of them is the propyl ion. If the carbon in the middle of the propyl is ionised, that's a secondary carbocation (it would have two alkyl - methyl - groups attached)