Chemistry synoptic edexcel!

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Ralfskini

Here are the answers:

b) Thermodynamic stability-products are at lower energy than reactants/ reaction would release energy were it kinetically unstable/
Kinetic stabillity- activation energy requirements too high/ other factors contribute, e.g. steric hindrance or no available vacant orbitals as in the case of tetrachloromethane.

isn't the definition of thermodynamic stability....

Thermodynamic stability - when the enthalpy level of the products is much hihger than the enthalpy level of the reactants.

?

Reply 21

DaveR

Ralfskini

d) Flame test- lilac flame for potassium salt/ yellow flame for sodium chloride

Think for 2nd mark you have to talk more about preparing the wire before the flame test. e.g. heat, then dip in conc H2SO4, then reheat until no colour produced when the wire is placed in the flame.

Reply 22

Ralfskini

DaveR

Think for 2nd mark you have to talk more about preparing the wire before the flame test. e.g. heat, then dip in conc H2SO4, then reheat until no colour produced when the wire is placed in the flame.

Yes, I did do that.

Reply 23

infekt

Ralfskini

Yes, I did do that.

u could just mention a clean nichrome or pt wire .... look at the lilac colour through blue cobalt glass to ensure clarity

Reply 24

infekt

will writing a lot make me lose marks ? ... i think i must have written 10 pages ....

Reply 25

Ralfskini

You definitely wont lose marks but it wasnt really necessary to write vast amounts.

Reply 26

infekt

Ralfskini

You definitely wont lose marks but it wasnt really necessary to write vast amounts.

i just thought ... tht since the paper is leaked .... section B must have been also ... nobody will leak a part of a paper .. so i wrote a lot .. .didnt leave n e points out ... jsut to make sure i go above the A ums

Reply 27

Ralfskini

infekt

Yes. Did you get handed an additional sheet instead of question 1? I don't see why they didn't change the whole paper considering if it has leaked then people will have seen questions 2,3 and 4 as well.

Reply 28

infekt

Ralfskini

my theory is tht ... if a person leaked a paper ..he must have been desperate ... face it .. a good student whos confident wont steal a paper ... if he gets full in section B and screws up piss easy section A then it would be pretty doubtful ... but its kinda unfair .. coz the first question was kinda tricky .. i know 2 3 brill people in my class who didnt get the x=6

Reply 29

Ralfskini

...unless of course it's a mechanism to try and determine people who have cheated as they will probably score poorly on the first question but do well on the rest of the paper.

Reply 30

infekt

Ralfskini

...unless of course it's a mechanism to try and determine people who have cheated as they will probably score poorly on the first question but do well on the rest of the paper.

my point exaclty .. buts its kinda unfair ... i mean .. god knows how many sit the paper .. there are 42 in my class alone ... its VERy likely ppl will get the first question wrong coz u had to do a lot of fiddling to get the answer

Reply 31

Ralfskini

infekt

Yeh, plus it's only 10 marks so it doesnt hold much weighting. 6 marks for a calculation!!

Ah well, at least it's over now. It will be interesting to see how many people blame their exam results on the leaked papers.

Reply 32

Dust

awww maan i got quite a few rong...
lol ah well... i;m freeeeee!!!!!!!
i dont care no more.. it aint like i;m gonna get the grades i need after the unit 5 exam anyways!

Reply 33

Dust

but 1 ene

i got that :smile:

lol

i;m usprised it was 6 marks and soo simple...
i was like dang, urm the whole time i was like i must b missin summin it must b harder :tongue:

lol

Reply 34

qqqwwweee

I did question 4!
The paper was quite easy as a whole

Reply 35

ianaf18

Ralfskini

Here are the answers:

1a) Ag+(aq)+Cl-(aq) -------> AgCl(s

It said in the question that all the Cl in carnllite or what ever it was called was preciptated so shouldnt the equation be x3?

I did question 4, wlthough i started question 3. When i realised how the marks were arranged for 3 i changed to do 4 since i had plenty of time.
Question 3 had about 4 or 5 high marke questions whereas question 4 has lots of smaller questions so if i got something wrong it would only lose me a few marks rather than losing loads.
But overall i thought it was much easier than i expected. The replacement question 1 i thought was much easier than the original even though the original didnt look too, even with the benzene stuff in it.

Reply 38

[_Z_]

i did question 1,3,4....... found the paper easy on the whole....
the changed question was pretty easy compared to the actual one.....
got x=6 ..... and only things i messed up were... the structure of aluminium chloride....(forgot that molar mass was given and drew alcl3)..... and the oxidation question(last part of q4).....hopin 4 an A... lets see.....