OCR chemistry A2 practical plan

Watch
This discussion is closed.
K-lou
Badges: 0
#1
Report Thread starter 16 years ago
#1
Anyone else doing this plan for this exam board?

Got to determine the standard enthalpy change of the following reaction via an indirect route.

Cu(s) + 2Hcl(aq) ------> CuCl2(aq) + H2

It gives a clue of using two reactions, one of which being the displacement of copper from copper (II) chloride. Apparently the best way to do it to use zinc, then construct a Hess' cycle? Can anyone help?

x
0
cobra
Badges: 14
Rep:
?
#2
Report 16 years ago
#2
theres alredy quite a big thread on this from a few days ago
0
Angel-Dude
Badges:
#3
Report 16 years ago
#3
hmmm you should try working it out for yerself really.....but what the hell:

- Use calorimeter experiment (polystyrene cup blah blah etc)
- Use Zinc to displace CuCl2 (you need to do a prelim to understand why zinc is the best metal to displace copper)
- Zn + CuCl2 ----> ZnCl2 + Cu
- Now work out the other reaction for yourself!
(hint: how else can you form ZnCl2 + another chemical e.g. one that relates to a chemical in the reaction Cu(s) + 2Hcl(aq) ------> CuCl2(aq) + H2?)
- Draw up an energy cycle
- Find ∆H using : ∆H = mxCpx∆T
- NOTE THAT THIS IS FROM AS CHEMISTRY 1 and NOT A2 Chemistry 2, which I find VERY VERY silly!!!

Ok thats all I can tell you for now, if u have more questions, do feel free to ask me providing they are not ones where I do all the work for you (e.g. "Can you show me yer method..."). Please dont constantly pm me, coz the chances are yer teacher is gonna be more helpful.
0
cobra
Badges: 14
Rep:
?
#4
Report 16 years ago
#4
(Original post by Angel-Dude)
hmmm you should try working it out for yerself really.....but what the hell:

- Use calorimeter experiment (polystyrene cup blah blah etc)
- Use Zinc to displace CuCl2 (you need to do a prelim to understand why zinc is the best metal to displace copper)
- Zn + CuCl2 ----> ZnCl2 + Cu
- Now work out the other reaction for yourself!
(hint: how else can you form ZnCl2 + another chemical e.g. one that relates to a chemical in the reaction Cu(s) + 2Hcl(aq) ------> CuCl2(aq) + H2?)
- Draw up an energy cycle
- Find ?H using : ?H = mxCpx?T
- NOTE THAT THIS IS FROM AS CHEMISTRY 1 and NOT A2 Chemistry 2, which I find VERY VERY silly!!!

Ok thats all I can tell you for now, if u have more questions, do feel free to ask me providing they are not ones where I do all the work for you (e.g. "Can you show me yer method..."). Please dont constantly pm me, coz the chances are yer teacher is gonna be more helpful.
Why is zinc peferable to magnesium i trialed magnesium and found no problems
0
Angel-Dude
Badges:
#5
Report 16 years ago
#5
lol, in that case your trial was well mucked up! I suggest retry with fresh samples, oh and perhaps a few protective shields......
0
cobra
Badges: 14
Rep:
?
#6
Report 16 years ago
#6
(Original post by Angel-Dude)
lol, in that case your trial was well mucked up! I suggest retry with fresh samples, oh and perhaps a few protective shields......
You dont have to use conc HCL, did you?
0
GCT
Badges: 0
#7
Report 16 years ago
#7
Since this takes place in an aqueous solution try writing two separate half cell equations and then convert deltal E to delta G.
0
cobra
Badges: 14
Rep:
?
#8
Report 16 years ago
#8
(Original post by GCT)
Since this takes place in an aqueous solution try writing two separate half cell equations and then convert deltal E to delta G.
delta G? if you mean gibbs free energy we dont do it in OCR
0
X
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Have you made your firm and insurance uni choices yet?

Yes (70)
53.44%
Yes, but I want to swap them (10)
7.63%
No, but I know who I want to choose (14)
10.69%
No, I still don't know who I want to choose (33)
25.19%
I have decided I don't want to go to uni anymore and will not be choosing (4)
3.05%

Watched Threads

View All