OCR B Salter's Chemistry by Design F335 - 15th June 2015 Watch

docdoc02
Badges: 2
Rep:
?
#161
Report 4 years ago
#161
(Original post by radhikagulati)
For NMR do you just talk about what the ppm value relates to and splitting? What else can you talk about?
for nmr i think if they give you a diagram showing the splitting then mention it, talk about the chemical shifts and number of proton which represents the area of the peak
0
reply
radhikagulati
Badges: 3
Rep:
?
#162
Report 4 years ago
#162
(Original post by docdoc02)
for nmr i think if they give you a diagram showing the splitting then mention it, talk about the chemical shifts and number of proton which represents the area of the peak
How do we know the number of proton that represent the area of the peak?
0
reply
docdoc02
Badges: 2
Rep:
?
#163
Report 4 years ago
#163
(Original post by radhikagulati)
How do we know the number of proton that represent the area of the peak?
they would give a number on top of each peak like 6H
0
reply
radhikagulati
Badges: 3
Rep:
?
#164
Report 4 years ago
#164
(Original post by docdoc02)
they would give a number on top of each peak like 6H
Oh yeah I've seen that before and then you can use it to find the proton ratio
Thank you!
0
reply
docdoc02
Badges: 2
Rep:
?
#165
Report 4 years ago
#165
(Original post by radhikagulati)
Oh yeah I've seen that before and then you can use it to find the proton ratio
Thank you!
yes basically
0
reply
Diamond Crafter
Badges: 2
Rep:
?
#166
Report 4 years ago
#166
(Original post by greencat55)
Sorry to ask again, but I'm stumped again. :/
Does anyone know how to get the answer to (ii). The mark scheme said it is 2.73.
Part (i) is right and please ignore my scribbles :P
Thank you!!

Posted from TSR Mobile
What paper is this from?
0
reply
Shostakovish
Badges: 12
Rep:
?
#167
Report 4 years ago
#167
So I don't get this.
In CI on page 105 it says -
'The density of ice at 273K is less than the density of water a the same temperature'
Huh??
Anyone help here?
0
reply
suyoof123
Badges: 2
Rep:
?
#168
Report 4 years ago
#168
(Original post by Shostakovish)
So I don't get this.
In CI on page 105 it says -
'The density of ice at 273K is less than the density of water a the same temperature'
Huh??
Anyone help here?
Correct me if im wrong but when ice is formed, the hydrogen bonds still exist but they are more spread out and there are large open spaces between water molecules in ice , hence they have a lower density than water.

I THINK he says
0
reply
greencat55
Badges: 2
Rep:
?
#169
Report 4 years ago
#169
(Original post by Diamond Crafter)
What paper is this from?
Jan 2012

Posted from TSR Mobile
0
reply
Shostakovish
Badges: 12
Rep:
?
#170
Report 4 years ago
#170
(Original post by suyoof123)
Correct me if im wrong but when ice is formed, the hydrogen bonds still exist but they are more spread out and there are large open spaces between water molecules in ice , hence they have a lower density than water.

I THINK he says

I get that part, but I meant the part where it says 'at the same temperature'Ice is just liquid water in another form though, right? I don't understand this.
0
reply
MattBrockle
Badges: 1
Rep:
?
#171
Report 4 years ago
#171
Anyone got the F335 June 2014 question paper & mark scheme please?
0
reply
suyoof123
Badges: 2
Rep:
?
#172
Report 4 years ago
#172
(Original post by Shostakovish)
I get that part, but I meant the part where it says 'at the same temperature'Ice is just liquid water in another form though, right? I don't understand this.
Thats it,

When water is in the form of ice, then those large empty spaces exist, they dont exist when water is in liquid form

so think of it as when water is ice, there is less 'water' in a certain space due to empty spaces but when water is 'water' and not ice, then those empty spaces dont exist, hence water has a higher density than ice.

Hope thats clear
1
reply
Shostakovish
Badges: 12
Rep:
?
#173
Report 4 years ago
#173
(Original post by MattBrockle)
Anyone got the F335 June 2014 question paper & mark scheme please?
Here you gooo ^.^
Attached files
0
reply
MattBrockle
Badges: 1
Rep:
?
#174
Report 4 years ago
#174
(Original post by Shostakovish)
Here you gooo ^.^
you are a very good person i wish you good health for the rest of your life
2
reply
Diamond Crafter
Badges: 2
Rep:
?
#175
Report 4 years ago
#175
(Original post by Shostakovish)
I get that part, but I meant the part where it says 'at the same temperature'Ice is just liquid water in another form though, right? I don't understand this.
(Original post by suyoof123)
Thats it,

When water is in the form of ice, then those large empty spaces exist, they dont exist when water is in liquid form

so think of it as when water is ice, there is less 'water' in a certain space due to empty spaces but when water is 'water' and not ice, then those empty spaces dont exist, hence water has a higher density than ice.

Hope thats clear
I think what she means is (or at least the part that got me) was the fact that it's understood that ice is less dense than water but it's the "at the same temperature" part as logically ice and water don't exist at the same temperature because the whole point of it being "ice" is that the temperature has been reduced to a point where water has changed state. However if the textbook meant in hypothetical terms that if water and ice were to exist in the same temperature then ice would be less dense than water due to the spaces that exist. I think! If I've just confused things even more then I'm sorry!
0
reply
MrPolish
Badges: 2
Rep:
?
#176
Report 4 years ago
#176
(Original post by Shostakovish)
So I don't get this.
In CI on page 105 it says -
'The density of ice at 273K is less than the density of water a the same temperature'
Huh??
Anyone help here?
yeah i think its a mistake, ive read that bit over few times and it doesnt make much sense for liquid water and ice to have a difference of density at the same temperature :P
0
reply
Shostakovish
Badges: 12
Rep:
?
#177
Report 4 years ago
#177
I dont feel ready.
1
reply
JakeDaw
Badges: 2
Rep:
?
#178
Report 4 years ago
#178
(Original post by Diamond Crafter)
I think what she means is (or at least the part that got me) was the fact that it's understood that ice is less dense than water but it's the "at the same temperature" part as logically ice and water don't exist at the same temperature because the whole point of it being "ice" is that the temperature has been reduced to a point where water has changed state. However if the textbook meant in hypothetical terms that if water and ice were to exist in the same temperature then ice would be less dense than water due to the spaces that exist. I think! If I've just confused things even more then I'm sorry!
But water does exist as both ice and liquid at the same temperature? On a cold day the top of a pond will freeze over but there will still be water underneath. In fact water exists as all three states at the same temperature, water vapour in the air, liquid as the pond, and solid as the frozen top of the pond (its even got a special name and occurs for other molecules as well - the triple point)
0
reply
JakeDaw
Badges: 2
Rep:
?
#179
Report 4 years ago
#179
With NMR spectroscopy I understand how the peaks split but how close do the next hydrogens have to be to have an effect on the splitting? Is it only the immediate neighbouring hyrdrogens?
0
reply
Turtlefushsia
Badges: 0
Rep:
?
#180
Report 4 years ago
#180
Sorry to burst in, but is phenylammine the same as aminobenzene?
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
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 East Anglia
    Undergraduate Open Day Undergraduate
    Sun, 20 Oct '19
  • University for the Creative Arts
    Undergraduate Open Day Undergraduate
    Sun, 20 Oct '19
  • University of Gloucestershire
    Undergraduate Open Day Undergraduate
    Sun, 20 Oct '19

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

Yes I know where I'm applying (56)
66.67%
No I haven't decided yet (18)
21.43%
Yes but I might change my mind (10)
11.9%

Watched Threads

View All