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AQA Chemistry Unit 4 with Anon_98

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Advantages and disadvantages of recycling polymers.

Advantages:

- Less oil (raw material) used for production.

- Less energy consume.

- Reduced emissions of e.g. CO₂ and SO_2.

Disadvantages:

- Kerbside collection of domestic plastic is costly.

- Sorting and separation is difficult and labour intensive.

Reply 121

Anon_98

Organic synthesis + analysis – applications – Topic 10.

be able to deduce how to synthesise organic compounds using the reactions in this specification be able to identify organic functional groups using the reactions in the specification.

I don't think I can make any notes on this bc they're practically telling me to do past papers. :rofl:

So, I'll skip to the next topic. :'3

Reply 122

Anon_98

Structure determination – Topic 11.

Carbon-13 NMR

If an atom has an odd mass number, it can possess a property called spin.

The structure reference used in NMR spectroscopy is Tetramethylsilane - (CH₃)₄Si

Each peak represents a different Carbon environment.

~

Proton NMR

Each peak represents a different hydrogen environment.

Why use TMS?

- It is Inert.
- Non-toxic.
- Volatile

Solvents.

- CDCl3 is used bc it will not interfere with the results.(proton free)

- CCl4

Reply 123

Anon_98

Structure determination - Chromatography – Topic 11.

Chromatography - A technique for separating the components of a mixture on the basis of the differences in affinities for a stationary phase(retention) and for a moving phase.

How can column chromatography be used to separate a mixture?

- Stationary phase: finely divided alumina in a column·

- Moving phase: usually an organic solvent(eluent) chosen to maximise separation·

- Mixture to be separated is washed through with the solvent.·

- Separation of the mixture depends on the balance between the solubility of a component in the solvent (moving phase) and its retention in the stationary phase.

How can gas-liquid chromatography can be used to separate mixtures of volatile liquids?

- Stationary phase: inert powder coated with non-volatile liquid packed into long narrow tube.

- Moving phase: carrier gas such as helium or nitrogen(eluent).

- Mixture to be separated is carried through with the carrier gas.·

- Separation of the mixture depends on the:

Solubility of a component in the non-volatile liquid (retention in the stationary phase), the flow rate of the carrier gas, the operating temperature and the length of the column.

- Separated components can be fed in to a mass spectrometer as they emerge for identification.

I've missed out mass spectrometry + Infrared bc that's from AS and basically just a repeat of unit 1 + 2 stuff + I cba.

(edited 7 years ago)

Reply 124

Anon_98

It's 4am but I've finally finisheddddd! :woo:

Reply 125

username1194172

Original post by Anon_98

It's 4am but I've finally finisheddddd! :woo:

ah congrats, thank you so much for this and good luck for tomorrow/today!!

Reply 126

Anon_98

Original post by Louisss

ah congrats, thank you so much for this and good luck for tomorrow/today!!

Thanks aha, didn't think I'd ever get it done at one point + you're more than welcome. - Glad you found it helpful + I wish you the best too! <3

Reply 127

Anon_98

Original post by Hydeman

Good luck, Anon! :jive:

Thank you. <3

Thanks + I'm sorry for being a little bit grouchy earlier. Hope you managed to get all your notes done, good luck for tomorrow too. <3

Original post by zahraaj1

good luck and thanks for these! :smile:

You're welcome. I'm glad you found them useful - good luck to you too!

Thanks a lot + I won't. :'3

Original post by TheOtherSide.

In case I haven't said this yet GOOD LUCK ON YOUR EXAM!! :jumphug:

And listen to AngryRedhead? :puppyeyes:

Thank you! <3

Reply 128

Anon_98

@Matt Johnson It's a bit late, but you asked about a Chem 4 thread a few days ago so I thought I'd let you know that I've finished it.

Reply 129

study2016

Great stuff! Good luck for today :smile:

Hopefully we can get a CHEM5 thread too? :tongue:

Reply 130

Anon_98

Original post by study2016

Great stuff! Good luck for today :smile:

Hopefully we can get a CHEM5 thread too? :tongue:

Thank you v much + good luck to you too. <3

Hopefully, yes. :tongue:

I'll probably start it after my last exam of this week, but not sure.

Reply 131

username1133132

Good luck thank you so much for the helpful threads!! Xx

Reply 132

Hatiki99

Genius anon - thanks man!

Reply 133

Anon_98

Original post by haj101

Good luck thank you so much for the helpful threads!! Xx

Original post by Hadigy

Genius anon - thanks man!

Ah, you're welcome. :blush:

Wish you all the best for the exam.

Reply 134

banna1998

What did everyone get for the last question the structure?

Reply 135

Zaherr2737

Exam was so bad think I got a U

Reply 136

matty9

[video="youtube;RXthYHvOSn0"]https://www.youtube.com/watch?v=RXthYHvOSn0[/video]

Hitler didn't revise well enough

Reply 137

Hatiki99

I think the last one is like this: ch3 - ch(ch3) - o - ch2 - ch2 - oh

Reply 138

bethl303

Original post by Anon_98

Okay, so I guess, for anyone who might be confused - this is another revision thread where I will be making my notes.

I'll tag the people who previously said they were interested once I've finished. Really hoping it won't take me too long bc I only have 2..and a bit..ish days + I'd like to spend one of those days memorising the info + doing the past papers.

:crazy: