Edexcel Chemistry A2 Unit 5 ~ Wednesday 19th June 2013 (Now Closed) Watch

Poll: How pumped up are you for this exam?-(warning)-(bad jokes arene this poll!)
"Titanium-I'm not going to corrode (even at high temperatures)" (A*) (22)
16.67%
"Benzene's my middle name, give me the paper in a week and I'll ace it!" (A) (27)
20.45%
"Yeah, I'm fairly electrophillic (positively charged) about the exam" (B) (27)
20.45%
"I'm in the middle of the salt bridge, but I will pass-eventually" (C) (21)
15.91%
"I'm feeling rather electroNegative about this exam" (D) (18)
13.64%
"Benzene, what's that?" (E) (6)
4.55%
"Chemistry, what's that?" (F) (11)
8.33%
This discussion is closed.
Dr. Django
Badges: 12
Rep:
?
#1101
Report 6 years ago
#1101
(Original post by Gnome :))
The electron configuration is 1s2 2s2 2p6 3s2 3p4
So from 1s2 2s2 2p6 and 3s2 you get 6 full orbitals
In 3p4 it's slightly different. Electrons "prefer" being on their own in this context due to electrostatic repulsion. The 3p subshell can have 3 pairs of electrons, or 3 orbits, so 3 electrons will go into separate orbitals. The remaining electron then has to join one of these electrons. So the 3p subshell is made of 3 orbitals; 2 with a single electron, one with a full orbital.
Therefore you have 7 full orbitals, and 2 half filled orbitals
Thank you so much for reminding me that they fill up one at a time! I completely forgot
0
phaseshift
  • Study Helper
Badges: 12
Rep:
?
#1102
Report 6 years ago
#1102
Not long now, how is everyone coping? I'm just about seeing the light at the end of the tunnel.
0
jojo1995
Badges: 2
Rep:
?
#1103
Report 6 years ago
#1103
(Original post by HarryMWilliams)
Not long now, how is everyone coping? I'm just about seeing the light at the end of the tunnel.

hopefully i'll be seeing that soon too I really want an A* but I can't seem to even get an A grade in unit 5. It's quite off putting - I think i'm trying hard, i guess i just need to change my strategy. Have you started papers yet?
0
phaseshift
  • Study Helper
Badges: 12
Rep:
?
#1104
Report 6 years ago
#1104
(Original post by jojo1995)
hopefully i'll be seeing that soon too I really want an A* but I can't seem to even get an A grade in unit 5. It's quite off putting - I think i'm trying hard, i guess i just need to change my strategy. Have you started papers yet?
Yah - I've done one or two, I'm focussing on the organic stuff at the moment. I quite like Unit 5 over the others, it's not 'easy' per se, but just nice.
0
jojo1995
Badges: 2
Rep:
?
#1105
Report 6 years ago
#1105
(Original post by HarryMWilliams)
Yah - I've done one or two, I'm focussing on the organic stuff at the moment. I quite like Unit 5 over the others, it's not 'easy' per se, but just nice.
yeah... you need to know the organic inside out - the jan grade boundaires are so high... for the one i just did, it was 80 FOR AN A* ??? WHY lol - I prefer unit 4 by 100%
0
jojo1995
Badges: 2
Rep:
?
#1106
Report 6 years ago
#1106
Hi, does anyone know how to calculate the percentage error of a beaker, pipette, thermometer and anything else please ? thank you in advance
0
Ryejd
Badges: 0
Rep:
?
#1107
Report 6 years ago
#1107
A hydrated transition metal ion is colourless. Which of the following could be the
electronic configuration of this ion?
A [Ar] 3d54s2
B [Ar] 3d8
C [Ar] 3d104s2
D [Ar] 3d10

why D and not C?
0
phaseshift
  • Study Helper
Badges: 12
Rep:
?
#1108
Report 6 years ago
#1108
(Original post by jojo1995)
yeah... you need to know the organic inside out - the jan grade boundaires are so high... for the one i just did, it was 80 FOR AN A* ??? WHY lol - I prefer unit 4 by 100%

I quite like Unit 4 too actually - A2 is far much more interesting and enjoyable than AS.
1
jojo1995
Badges: 2
Rep:
?
#1109
Report 6 years ago
#1109
(Original post by Ryejd)
A hydrated transition metal ion is colourless. Which of the following could be the
electronic configuration of this ion?
A [Ar] 3d54s2
B [Ar] 3d8
C [Ar] 3d104s2
D [Ar] 3d10

why D and not C?

ion means it has lost electrons, and transition metals have thier outer electrons in 3d and 4s sub shells. so in order for it to be an ion it must have lost some electrons. electrons are lost from the 4s first

hopefully i've answered your question, i am quite bad at explaining.
0
shumen9523
Badges: 6
Rep:
?
#1110
Report 6 years ago
#1110
(Original post by Ryejd)
A hydrated transition metal ion is colourless. Which of the following could be the
electronic configuration of this ion?
A [Ar] 3d54s2
B [Ar] 3d8
C [Ar] 3d104s2
D [Ar] 3d10

why D and not C?
Hey,
C displays the electron configuration of an atom of zinc as the s-subshell is full.
D on the other hand does not have any electrons in the s-subshell which indicates that 2 electrons had been lost. This shows that it is the transition metal ion.
0
Tackla
Badges: 14
Rep:
?
#1111
Report 6 years ago
#1111
Guys how are unit 5 papers? I done most of my revision,but haven't done a single paper yet. It looks scary lol :no:

Posted from TSR Mobile
0
phaseshift
  • Study Helper
Badges: 12
Rep:
?
#1112
Report 6 years ago
#1112
(Original post by Tackla)
Guys how are unit 5 papers? I done most of my revision,but haven't done a single paper yet. It looks scary lol :no:

Posted from TSR Mobile
The January 2013 (I think) paper with the copper question... good luck!

Otherwise, they aren't too bad. Some of the organic questions are just repeated (effectively) in each paper so I would suggest you learn those verbatim.
0
LeaX
Badges: 20
Rep:
?
#1113
Report 6 years ago
#1113
Hey, could someone please just check my thought process is correct.

When a redox reaction produces a solid, the equilibrium moves to the right (so the constant increases) so the value for the cell's emf will increase? Which explains why, despite a negative Ecell, it could still occur?
0
ayeswary
Badges: 0
Rep:
?
#1114
Report 6 years ago
#1114
(Original post by jojo1995)
Hi, does anyone know how to calculate the percentage error of a beaker, pipette, thermometer and anything else please ? thank you in advance
Hi to calculate the percentage error for the apparatus
%error
= the uncertainty in the equipment divided by the reading an then you times 100%

This kind of questions they will sometimes give you the titre reading so u use that and divide with the reading and times with 100%.
Hope you understand what I meant. If you don't then let me know yeah.
Cheers. 😊
If they don't give you the titre reading then u have to calculate it by yourself where you 2 times with the uncertainty of the equipment and then divide with the reading and times with 100%.



Posted from TSR Mobile
0
jojo1995
Badges: 2
Rep:
?
#1115
Report 6 years ago
#1115
(Original post by ayeswary)
Hi to calculate the percentage error for the apparatus
%error
= the uncertainty in the equipment divided by the reading an then you times 100%

This kind of questions they will sometimes give you the titre reading so u use that and divide with the reading and times with 100%.
Hope you understand what I meant. If you don't then let me know yeah.
Cheers. 😊
If they don't give you the titre reading then u have to calculate it by yourself where you 2 times with the uncertainty of the equipment and then divide with the reading and times with 100%.



Posted from TSR Mobile

Thank you so much do you know how I'd calculate the uncertainty ?
0
Gnome :)
Badges: 2
Rep:
?
#1116
Report 6 years ago
#1116
(Original post by jojo1995)
Thank you so much do you know how I'd calculate the uncertainty ?
So if you have a burette that measures to 0.1cm3, you uncertainty is +/- 0.05, so 0.05*2=0.1
0
JRP95
Badges: 2
Rep:
?
#1117
Report 6 years ago
#1117
(Original post by Gnome :))
So if you have a burette that measures to 0.1cm3, you uncertainty is +/- 0.05, so 0.05*2=0.1
What? In physics the uncertainty is = the smallest scale division that your equipment measures why is it now the uncertainty is that/2? (shouldnt the uncertainty of the burette be 0.1cm3?
0
ayeswary
Badges: 0
Rep:
?
#1118
Report 6 years ago
#1118
(Original post by JRP95)
What? In physics the uncertainty is = the smallest scale division that your equipment measures why is it now the uncertainty is that/2? (shouldnt the uncertainty of the burette be 0.1cm3?
Yes the smallest division for the burettte is 0.1 cm3. But to calculate the percentage error we use the uncertainty which is the smallest division divided by 2. In other words 0.1/2 = 0.05 cm3. Uncertainty is an estimate attached to a measurement which characterizes the range of values within which the true value is said to lie. That's why we use 0.05 instead of 0.1. Well in physics is a different thing. I am not too sure about physics cause have dropped the subject and only focussing on the other two sciences. So hope u understand yeah.
Cheers


Posted from TSR Mobile
0
GeorgeL3
Badges: 5
Rep:
?
#1119
Report 6 years ago
#1119
(Original post by JRP95)
What? In physics the uncertainty is = the smallest scale division that your equipment measures why is it now the uncertainty is that/2? (shouldnt the uncertainty of the burette be 0.1cm3?
The calculation you need is:
(Uncertainty in equipment / Total amount measured) x 100 = % uncertainty

Remember that when reading a burette you take a reading twice (Start and end of titration) so you need to multiply the uncertainty by 2. It's also worth just remembering that the standard uncertainty for a burette is ±0.05cm3

So for example if you did a titration and got a titre value of 10cm3, the uncertainty would be:
2 x (0.05/10) x 100 = 1%
0
severus.snape
Badges: 0
Rep:
?
#1120
Report 6 years ago
#1120
what exactly do you mean by synoptic by the way? :P I am new to A2 :/
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

University open days

  • University of Bristol
    Undergraduate Open Afternoon Undergraduate
    Wed, 23 Oct '19
  • University of Exeter
    Undergraduate Open Day - Penryn Campus Undergraduate
    Wed, 23 Oct '19
  • University of Nottingham
    Mini Open Day Undergraduate
    Wed, 23 Oct '19

Have you made up your mind on your five uni choices?

Yes I know where I'm applying (138)
61.61%
No I haven't decided yet (50)
22.32%
Yes but I might change my mind (36)
16.07%

Watched Threads

View All