SUGGESTED ANSWERS!!!

[illuminati]

I drew the graph starting at 0 instead of .06 absorbance for some stupid reason!!! I used that date to find the mg, how many marks will I lose out of the maximum four??

you'll get consequential, so at least 1, but maybe 2.

[rocket]

Thanks heaps!

[davo_10]

For 3b, name the functional groups that link the monomers, will they accept ether linkages as the answer?

[arikupe2]

for question 4C of Section B didn't you need to include fractional distillation? it asked for a pure sample of propyl propanoate and the reaction of 1-propanol with propanoic acid isn't a 100% reaction so you'd have some reagents left over, you'd need to separate the ester from the left-over acid/alcohol and the water that's produced with it... no?

[Tonychet2]

For 3b, name the functional groups that link the monomers, will they accept ether linkages as the answer?

there are no ether linkages.

[Tonychet2]

for question 4C of Section B didn't you need to include fractional distillation? it asked for a pure sample of propyl propanoate and the reaction of 1-propanol with propanoic acid isn't a 100% reaction so you'd have some reagents left over, you'd need to separate the ester from the left-over acid/alcohol and the water that's produced with it... no?

yes probably , crap there goes another mark... hoping for 73/75 now lol

[charmanderp]

for question 4C of Section B didn't you need to include fractional distillation? it asked for a pure sample of propyl propanoate and the reaction of 1-propanol with propanoic acid isn't a 100% reaction so you'd have some reagents left over, you'd need to separate the ester from the left-over acid/alcohol and the water that's produced with it... no?

yes probably , crap there goes another mark... hoping for 73/75 now lol

No because the question was about verifying that what we had was pure. Not how we would make it pure. Mentioning fractional distillation at that stage would be irrelevant.

[Tonychet2]

for question 4C of Section B didn't you need to include fractional distillation? it asked for a pure sample of propyl propanoate and the reaction of 1-propanol with propanoic acid isn't a 100% reaction so you'd have some reagents left over, you'd need to separate the ester from the left-over acid/alcohol and the water that's produced with it... no?

yes probably , crap there goes another mark... hoping for 73/75 now lol

No because the question was about verifying that what we had was pure. Not how we would make it pure. Mentioning fractional distillation at that stage would be irrelevant.

oh yeah thats right, woot might be able to get 74 if markers arent harsh

[Croc]

Hey guys, with question 4d, do you think TLC would be an acceptable answer? My reasoning is that if only one spot shows up on a chromatogram then it should be considered pure. What do you guys think?

[charmanderp]

There's a chance that not all the substances would show up in a TLC even if they were present, as they might be colourless. Normally we'd add ninhydrin or develop it under UV light but again these might not work for all substances, including propyl propanoate, propan-1-ol and propanoic acid.

[Croc]

Well, hopefully the examiners don't have as much knowledge as you do and accept the answer

[vagrantshades]

for question 4C of Section B didn't you need to include fractional distillation? it asked for a pure sample of propyl propanoate and the reaction of 1-propanol with propanoic acid isn't a 100% reaction so you'd have some reagents left over, you'd need to separate the ester from the left-over acid/alcohol and the water that's produced with it... no?

yes probably , crap there goes another mark... hoping for 73/75 now lol

No because the question was about verifying that what we had was pure. Not how we would make it pure. Mentioning fractional distillation at that stage would be irrelevant.

In 4C you had to mention how to make it pure. The reaction between propanoic acid and 1-propanol produced water, and thus pure propyl propanoate wasn't produce. The question was worth 3 marks. 1 mark for making propanoic acid, 1 mark for making the ester, and 1 mark for obtaining a pure sample of the ester.
Pure was bolded guys. It's what made fractional distillation necessary.

[WhoTookMyUsername]

i said HPLC (lol)

[joseph95]

was the ester a solid? could you have said dry off the water lol?

[SJC]

For stearic acid the state should be (s) since it is saturated? right???