but on a serious note though, if asked why toluene is more reactive than benzene, how do we phrase that the methyl group increases the ring's electron density? Saying it "donates" electrons sounds kinda dodgy...

Reply 1407

C0balt

16

Original post by samb1234

are we allowed to use trinitrotoluene for the attack or is that cheating?

As long as we wear gloves lab coat and goggles the risk and hazard should be lowered enough. Oh make sure you carry out the attack in the fume cupboard too.

Reply 1408

Ayman!

15

Original post by samb1234

Yeah it wasn't too bad, hopefully won't have lost too many marks. I have pretty extensive notes for chem 5 already so probably just doing papers for it tbh and reading over my notes (although I need to prioritise some other subjects a bit more atm) so that I should be ready to go by the exam. How did yours go?

There was a dibasic titration curve on ours along with sketching an NMR and designing a rate experiment involving the Arrhenius equation worth a tonne of marks. I have the general ideas on all of those correct but since they haven't be tested before, I have no idea how much I'll lose on each. :tongue:

I might lose 1-2 on the titration curve because my volume axis stuff probably wasn't very accurate and 1 on the NMR because of the height of my peaks. Losing a couple of marks here and there, I'm predicting myself a 75 (might be a little generous :tongue:

). Wasn't too bad in my opinion, but definitely a little challenging - I enjoyed it though haha

I'll be bothering you with a few U5 questions later on if you don't mind. :tongue:

I'm currently doing the 2013 paper.

Reply 1409

samb1234

OP

13

Original post by Ayman!

There was a dibasic titration curve on ours along with sketching an NMR and designing a rate experiment involving the Arrhenius equation worth a tonne of marks. I have the general ideas on all of those correct but since they haven't be tested before, I have no idea how much I'll lose on each. :tongue:

I might lose 1-2 on the titration curve because my volume axis stuff probably wasn't very accurate and 1 on the NMR because of the height of my peaks. Losing a couple of marks here and there, I'm predicting myself a 75 (might be a little generous :tongue:

). Wasn't too bad in my opinion, but definitely a little challenging - I enjoyed it though haha

I'll be bothering you with a few U5 questions later on if you don't mind. :tongue:

I'm currently doing the 2013 paper.

I'll probably have to look them up in my notes to refresh lol but sure ask ahead. Sounds like your paper will have lowish boundaries as well then

Reply 1410

Science&Despair

1

Original post by Hdb

Thanks bro, really need to do well in unit 5 since I've only scraped an A* in practical too :/

Same Dropped a couple UMS i shouldnt have in practical so prob need 86% UMS in unit 5 for an A, i can hope XD

Reply 1411

Fahad78636

3

Hey, does anyone know where I can get hold of the unit 4 paper we did or an unofficial mark scheme?

Reply 1412

iwant

2

Original post by lfcrules

Ibthink ln (1/time) is ok in the y axis as 1/time is proprtional to rate.

Yeh very true

Reply 1413

kevinchan1

1

Original post by Hdb

How do you know they're raising the grade boundaries? Hope it is 74 for an A* 🙏🏻

I would assume so considering they have been increasing over the last few years but I'm probably wrong on this. It'll be better to be pessimistic :biggrin:

Reply 1414

nerdygeek101

8

Original post by C0balt

Hopefully not as carcinogenic as benzene

Sorry to bother, you seem to know a lot, I think I may have missed out saying ln (1/t) and just said 1/t but said everything about gradient etc. and -Ea/R- will I most probably lose most marks?!

Reply 1415

C0balt

16

Original post by nerdygeek101

Sorry to bother, you seem to know a lot, I think I may have missed out saying ln (1/t) and just said 1/t but said everything about gradient etc. and -Ea/R- will I most probably lose most marks?!

No worries ☺
Um I think you'll lose a mark for sure for not plotting lnrate against 1/T (or ln1/t against 1/T possibly). I'm not sure what other 5 marks would be for so I can't say for definite
I'd stop worrying about it now and focus on the incoming unit 5
Good luck

Reply 1416

Wunderbarr

16

Original post by Don Pedro K.

but on a serious note though, if asked why toluene is more reactive than benzene, how do we phrase that the methyl group increases the ring's electron density? Saying it "donates" electrons sounds kinda dodgy...

Inductive effect since it's an alkyl chain?

Reply 1417

sabahshahed294

12

Hi!

I just wanted to ask about the electrophilic substituition of benzene. I know how to do it but I'm just confused regarding this.

https://a5c076379da85d2c0b501a60f1a40f8eeaf5f812.googledrive.com/host/0B1ZiqBksUHNYdEFJbUVsVUl3Ums/January%202011%20QP%20-%20Unit%205%20Edexcel%20Chemistry.pdf

In question 15(aii),I got this right while solving but shouldn't we use a catalyst which has Br in it like Iron(III) Bromide since we have to break the C-Br bond here. Why did they use AlCl3 here instead?

Reply 1418

ayvaak

2

AlCl3 and FeBr3 are known for being halogen carriers. It shouldnt matter if its with a Cl , Br or I for that matter

Posted from TSR Mobile

Reply 1419

sabahshahed294

12

Original post by ayvaak

AlCl3 and FeBr3 are known for being halogen carriers. It shouldnt matter if its with a Cl , Br or I for that matter

Posted from TSR Mobile

Oh. I thought there was some sort of a rule in which it matters that you use specific halogen carriers to break the specific carbon-halogen bonds in order to form a nucleophile. Thanks a lot. :smile:

Edexcel A2 Chemistry Exams -6CH04 (14th June) and 6CH05 (22nd June) Discussion Thread

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you