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AQA CHEM5 A2 Chemistry - 19th June 2013

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I can't stop crying

Original post by Pinkhead

i thought it asked you to suggest an experiment to prove that the bonding is ionic?

There were a couple about MgO. One was that question, then another asked you to show a reaction demonstrating it as a base

Reply 2482

SpiggyTopes

Original post by cat-lover

I highly doubt that. XD I've probably dropped a lot more anyway but just can't remember. I do need an A* though because I got a C in chemistry unit 4 because I got food poisoning. :frown:

Look at the past boundaries on the AQA website it's usually about 81 for an A*

Reply 2483

loknath

I'm sorry the examiner was obviously going through a divorce so he intended to take his revenge on me
Kill me

Reply 2484

Pinkhead

Original post by SpiggyTopes

You did, you melt it and if it conducts then it's ionic. :-)

damn... I just said try to dissolve it in water, LOL. I was pushed for time so i wrote the first time that came to mind: solubility.

Reply 2485

Anshul91

Anyone know what the overall UMS is for each grade boundary please?

Reply 2486

Xiomara

Original post by extons

CH3CHO + Co3+ + H2O > Co2+ + CH3COOH + 2H+ + e-
2H+ + CH3CHO + O2 + Co2+ + e- > Co3+ + CH3COOH + H2O

Two catalytic equations.

I used [Co(H2O)6]2+ in place of Co2+, will I still get the marks?

Reply 2487

Az_016

I didn't have any electrons in the question involving cobalt as a catalyst

Posted from TSR Mobile

Reply 2488

loknath

Ive lost about 25 marks so a B/C ****tttttt
Bye bye university

Reply 2489

cat-lover

Original post by SpiggyTopes

Look at the past boundaries on the AQA website it's usually about 81 for an A*

Well hopefully it's lower this year and I haven't made anymore stupid mistakes. :smile:

Reply 2490

Croydon'Stepper

Original post by dizzy17

what was the equation and colours for the aluminium in excess ammonia?

Well I put:

[Al(H2O)6]3+ + 6NH3 --> [Al(OH)6]3- + 6NH4+

From colourless soln to colourless soln (although white ppt is formed, it redissolves).

Reply 2491

mulac1

Original post by Az_016

I didn't have any electrons in the question involving cobalt as a catalyst

Posted from TSR Mobile

thats correct - you weren't supposed to have any :smile:

The guy that posted before is obviously dead clever cos he got the correct ratio.. but I am rather confident that his coblat answers are wrong :P sorry :smile:

Reply 2492

Dirtybit

Original post by Anshul91

Anyone know what the overall UMS is for each grade boundary please?

How can anyone possibly know that when they haven't been released yet?

Why neg for telling the truth? Klkl

(edited 10 years ago)

Reply 2493

Pinkhead

Original post by loknath

If lost about 25 marks so a B/C ****tttttt
Bye bye university

that would be an A even with high boundaries mate

Reply 2494

Croydon'Stepper

Original post by loknath

Ive lost about 25 marks so a B/C ****tttttt
Bye bye university

75 is usually an A, ****ing hell.

Reply 2495

Dirtybit

What was the answer to why was CO2 released or something like that the one marker?

Reply 2496

marleyxd

Original post by loknath

Ive lost about 25 marks so a B/C ****tttttt
Bye bye university

75/100 was a high A last year

Reply 2497

SpiggyTopes

Original post by Pinkhead

damn... I just said try to dissolve it in water, LOL. I was pushed for time so i wrote the first time that came to mind: solubility.

That might be right too. It depends if the molecule is soluble or not. I can't remember what the molecule was so don't know if it's soluble. :-) Fingers crossed it's soluble!

Reply 2498

Jellydev

Original post by mulac1

yes I suppose you could have done that ... but it doesnt really react with water...
I reacted it with HCl to give MgCl2 and water

Maybe it was a mark for h2o as steam

Reply 2499

Simonthegreat

Original post by loknath

I can't stop crying

Cheer up

It can't be that bad. Don't worry, It was a tough paper and I too struggled despite all the revision I put in.

Lets hope the grade boundaries are lower if everyone found it very hard. :smile: