OCR Salters: Chemistry of Materials Revision thread

OP

Olibert

I'm in the process of titrations to determine paracetamol content in various formulations. The reason it all went tits up was that, I planned to synthesise my own and then do comparisons etc... But after two attempts, I got stuck on the same stage and the damn stuff just wouldn't cook :mad:

Ooo thats sounds really interesting. I love all that sort of stuff, like biochemistry and pharmacology, and the analytical chemistry of pharmaceuticals (this is why I'm going into pharmacy with any luck haha). It does seem very difficult. Well think of it this way, you will have a lot to analyse and evaluate where you could pick up loads of marks and get a very good grade :biggrin:

Did you use ready-manufactured paracetamol in the end?

Reply 562

Loz17

Ooo thats sounds really interesting. I love all that sort of stuff, like biochemistry and pharmacology, and the analytical chemistry of pharmaceuticals (this is why I'm going into pharmacy with any luck haha). It does seem very difficult. Well think of it this way, you will have a lot to analyse and evaluate where you could pick up loads of marks and get a very good grade :biggrin:

Did you use ready-manufactured paracetamol in the end?

Yeah, that's the hope...Lot's to right about in the evaluation. :yep:

And yes, I'm now using ready manufactured stuff. I had 3 refluxing kits set up on monday so that I could get at least 3 different paracetamol formulations ready for titration. The titration is so difficult though because the end point is really not very obvious.

Reply 563

OP

Olibert

Yeah, that's the hope...Lot's to right about in the evaluation. :yep:

And yes, I'm now using ready manufactured stuff. I had 3 refluxing kits set up on monday so that I could get at least 3 different paracetamol formulations ready for titration. The titration is so difficult though because the end point is really not very obvious.

Oh my goodness, thats a lota paracetamol being made hehe. I never knew it could be made via reflux :smile:

And I though that with mine too, I think that my endpoint was wrong coz everywhere I read it was ment to be colourless, but it never did, so i made a loical endpoint basied on my researcg. it seemed to work and my results seem, no anolimlies as far as I can see :smile:

Reply 564

Loz17

Hehe my plan is on about 20 pages and implementation is on the same as yours atm. But currently working on it so will increase in the next hour or so. (well the plan will)

I wish I knew the meaning of the word 'concise' lol. I write loads

But I agree, anything 30> (well possibly 40 is 50 in my case) is a little unnecessary

What did you both do for your investigations?

Volume of vitamin C in orange juice, it require **** loads of titrations,
what about you?

Reply 565

Loz17

Oh my goodness, thats a lota paracetamol being made hehe. I never knew it could be made via reflux :smile:

And I though that with mine too, I think that my endpoint was wrong coz everywhere I read it was ment to be colourless, but it never did, so i made a loical endpoint basied on my researcg. it seemed to work and my results seem, no anolimlies as far as I can see :smile:

Not made, extracted :smile:

I waish making it were that simple. :eek3:

Reply 566

vinsta

Volume of vitamin C in orange juice, it require **** loads of titrations,
what about you?

My friend is doing that with Apple juice. Using dc pip or something? He spent the last 3 weeks doing titration after titration after titration :biggrin:

Reply 567

Olibert

My friend is doing that with Apple juice. Using dc pip or something? He spent the last 3 weeks doing titration after titration after titration :biggrin:

Yep, good old DC f*cking PIP, I went through 4 bottles of that s***.
Took 30 hours in the lab aswell, everyone else had left, and i was on my own with the random moderator hired off the street. Not cool.

Reply 568

vinsta

Yep, good old DC f*cking PIP, I went through 4 bottles of that s***.
Took 30 hours in the lab aswell, everyone else had left, and i was on my own with the random moderator hired off the street. Not cool.

Haha, I reckon on another 5 hours for me. But we don't have random moderators... :wink:

Reply 569

Fi0na.

Olibert

Someone's coursework I had a read through from last year is 55 pages. :eek:

Last year for our skills for chemistry piece, doing a titration, again the same persons coursework was about 40 pages, I thought **** it there is no way I can write that.

10 pages late...I got 40/45 for it :yep:

Just goes to prove it's quality not quanitity.

I wrote 5 or 6 pages for that :eek:

42/45

Hehe good luck everyone! I'm currently avoiding revision on the Aspects of Agriculture for a mid-unit test tomorrow morning! Hehe.

Oh I did my investigation on the Iodine Clock reaction.. so glad it's over, it was such a nightmare! And believe me, you will end up writing **** loads!! :woo:

Reply 570

Olibert

Haha, I reckon on another 5 hours for me. But we don't have random moderators... :wink:

Well, he just sat there as if he'd just smoked some weed for the last hour tbh. I could've photocopied my results and distributed them amongst the class and he would have just sat there staring out the window :rolleyes:

Reply 571

OP

vinsta

Volume of vitamin C in orange juice, it require **** loads of titrations,
what about you?

Exactly the same

I made up half the results though :s-smilie:

Reply 572

OP

Olibert

Not made, extracted :smile:

I waish making it were that simple. :eek3:

I hope it will all go ok for you though

Reply 573

Loz17

Exactly the same

I made up half the results though :s-smilie:

same

But my results are perfect :biggrin:

Reply 574

OP

vinsta

same

But my results are perfect :biggrin:

Hehe same

well once the experiment actually worked hehe

The apple juice is a different matter though...

Theres like no vitamin C in it whatsoever (my endpoint wasn't colourless, no matter how much I tried)

Reply 575

Loz17

Hehe same

well once the experiment actually worked hehe

The apple juice is a different matter though...

Theres like no vitamin C in it whatsoever (my endpoint wasn't colourless, no matter how much I tried)

I have no idea on the finer details, but isn't DC PIP a reducing agent. Some apple juices have ascorbic acid in them which is an anti oxidising agent, so is there a chance that the DC PIP itself is being prevented from oxidising by the ascorbic acid? Hence why you had to make up results :tongue:

Reply 576

OP

Olibert

I have no idea on the finer details, but isn't DC PIP a reducing agent. Some apple juices have ascorbic acid in them which is an anti oxidising agent, so is there a chance that the DC PIP itself is being prevented from oxidising by the ascorbic acid? Hence why you had to make up results :tongue:

No DCPIP is the oxidising agent as it gets reduced by the released protons from the oxidised ascorbic acid. However the apple juice i used reacted within like 0.2cm^3 of DCPIP

I am worried about these results though :s-smilie:

My orange juice was fine :smile:

.

I had to make up the results coz there was far to many titrations, and I was titrating all solutions under time pressure (with eqauted to about having to do 18 titrations in an hour, as well as settung up the equipment and making the DCPIP solution up each time)

Reply 577

Loz17

Hehe same

well once the experiment actually worked hehe

The apple juice is a different matter though...

Theres like no vitamin C in it whatsoever (my endpoint wasn't colourless, no matter how much I tried)

My endpoint should have been pink lol.

Reply 578

OP

vinsta

My endpoint should have been pink lol.

Same hehe, I read today thats coz its not pure DCPIP, there is other factors in there that make it pink when its reached and not colourless

I'm slightly worried about "My endpoint should have been pink" :s-smilie:

Reply 579