Edexcel (IAL) Unit 2 Chemistry June 10th

Watch
wenogk
Badges: 6
Rep:
?
#1
Report Thread starter 4 years ago
#1
Hi guys!
So I created this thread for unit 2 chem. Let's revise, share our ideas and clear our doubts here!
1
reply
katenell
Badges: 4
Rep:
?
#2
Report 4 years ago
#2
hello
any useful links to study ?


I need a study plan please
0
reply
wenogk
Badges: 6
Rep:
?
#3
Report Thread starter 4 years ago
#3
(Original post by katenell)
hello
any useful links to study ?


I need a study plan please
Hey, http://www.chemguide.co.uk is a good website it has alot of resources... I guess your main study plan should be to do past papers and learn from your mistakes, that's what I'm doing anyways
1
reply
t
Badges: 13
Rep:
?
#4
Report 4 years ago
#4
CGP is the number one life saver for anyone!! Like seriously if you don't have it go borrow it, buy it whatever it takes just to read the CGP book (for Edexcel). It includes everything you need to know for the exam and especially helps for last minute revision.
1
reply
katenell
Badges: 4
Rep:
?
#5
Report 4 years ago
#5
(Original post by wenogk)
Hey, http://www.chemguide.co.uk is a good website it has alot of resources... I guess your main study plan should be to do past papers and learn from your mistakes, that's what I'm doing anyways
thanks dude
0
reply
katenell
Badges: 4
Rep:
?
#6
Report 4 years ago
#6
(Original post by I <3 WORK)
CGP is the number one life saver for anyone!! Like seriously if you don't have it go borrow it, buy it whatever it takes just to read the CGP book (for Edexcel). It includes everything you need to know for the exam and especially helps for last minute revision.
what is the cgp ?
the blue book or the pink or what??
0
reply
t
Badges: 13
Rep:
?
#7
Report 4 years ago
#7
(Original post by katenell)
what is the cgp ?
the blue book or the pink or what??
Name:  81zj2U4AtcL._SL1500_.jpg
Views: 332
Size:  172.1 KB

This is the exact appearance of the book.
1
reply
Hiyoriiki
Badges: 2
Rep:
?
#8
Report 4 years ago
#8
do you think nucleophilic substitution of ammonia is an important topic?
0
reply
wenogk
Badges: 6
Rep:
?
#9
Report Thread starter 4 years ago
#9
(Original post by Hiyoriiki)
do you think nucleophilic substitution of ammonia is an important topic?
Yes it is and can be asked this time because the always ask the alcoholic and aqueous KOH qquestion..
0
reply
Sunethra
Badges: 5
Rep:
?
#10
Report 4 years ago
#10
(Original post by I <3 WORK)
Name:  81zj2U4AtcL._SL1500_.jpg
Views: 332
Size:  172.1 KB

This is the exact appearance of the book.
Where can I get this from? For free?
0
reply
t
Badges: 13
Rep:
?
#11
Report 4 years ago
#11
(Original post by wenogk)
Yes it is and can be asked this time because the always ask the alcoholic and aqueous KOH qquestion..
Is it required to know the mechanism for this reaction?
0
reply
t
Badges: 13
Rep:
?
#12
Report 4 years ago
#12
(Original post by Sunethra)
Where can I get this from? For free?
Well it depends where your location is. Most countries should have the facility of a local library where you may borrow books for free. However a lot of countries don't actually have this facility unfortunately.
0
reply
Arzam45
Badges: 5
Rep:
?
#13
Report 4 years ago
#13
The ion that gives a bleaching property is ClO- or OCl- ? Or are they the same?
0
reply
t
Badges: 13
Rep:
?
#14
Report 4 years ago
#14
(Original post by Arzam45)
The ion that gives a bleaching property is ClO- or OCl- ? Or are they the same?
Technically they should be the same because the charge applies to the whole compound and not individual atoms. However it is much more preferable and accurate to write it as ClO- because apparently the current chemical formula naming system is according to the alphabetical order of elements. It is called the 'Hill' system for your further information and interest.
0
reply
Arzam45
Badges: 5
Rep:
?
#15
Report 4 years ago
#15
(Original post by I <3 WORK)
Technically they should be the same because the charge applies to the whole compound and not individual atoms. However it is much more preferable and accurate to write it as ClO- because apparently the current chemical formula naming system is according to the alphabetical order of elements. It is called the 'Hill' system for your further information and interest.
Thanks a lot mate
0
reply
username2640413
Badges: 3
Rep:
?
#16
Report 4 years ago
#16
Heyy guys, so i seriously am confused about something. Okay so the thermal stability of group two carbonates and nitrates increases down the group making it more difficult to decompose. I am unsure of the reason for this... It is because

A) at top of group the ions are smaller will a larger charge ( large charge density) and therefore result in a stronger force of attraction between the metal ion and the O2 minus of the carbonate ion thus the energy released when those two come together is great and very exothermic. And it states that for a chemical reaction to occur the erergy released when bonds are formed( when O2 minus amd metal ion meet ) must be greater then the energy required to break bonds. Therefore as a smaller metal ions is more exothermic when it meets a O2minus ion ,less additional energy is required for the reaction to take place at top of group but as you go down more additional energy is required as the reaction is less exothermic.

Or is the reason

B) a smaller metal ion at the top of the group with a large charge density has a greater polarising effect on the carbonate ions electrons thus making the bond weaker and easier to break and hence less engery required at top of group and more at bottom ???

I seriously need help becasue the text book pushes more for the first answer but my teacher for the other ....???? 😱😱😱
0
reply
Sunethra
Badges: 5
Rep:
?
#17
Report 4 years ago
#17
(Original post by Mimiastc)
Heyy guys, so i seriously am confused about something. Okay so the thermal stability of group two carbonates and nitrates increases down the group making it more difficult to decompose. I am unsure of the reason for this... It is because

A) at top of group the ions are smaller will a larger charge ( large charge density) and therefore result in a stronger force of attraction between the metal ion and the O2 minus of the carbonate ion thus the energy released when those two come together is great and very exothermic. And it states that for a chemical reaction to occur the erergy released when bonds are formed( when O2 minus amd metal ion meet ) must be greater then the energy required to break bonds. Therefore as a smaller metal ions is more exothermic when it meets a O2minus ion ,less additional energy is required for the reaction to take place at top of group but as you go down more additional energy is required as the reaction is less exothermic.

Or is the reason

B) a smaller metal ion at the top of the group with a large charge density has a greater polarising effect on the carbonate ions electrons thus making the bond weaker and easier to break and hence less engery required at top of group and more at bottom ???

I seriously need help becasue the text book pushes more for the first answer but my teacher for the other ....???? 😱😱😱
As you go down the group thermal stability increases because the size of the cation increases and the nuclear charge decreases and a result the charge density decreases. This means that the polarizing power decreases down the group with decrease in charge density. As a result the ability of the cation to distort the anion is weak as a result we say that the compunds become more ionic down the group. As a result compounds are more stable thus a large about of energy needs to be supplied to decompose the carbonate or nitrate.
0
reply
username2640413
Badges: 3
Rep:
?
#18
Report 4 years ago
#18
(Original post by Sunethra)
As you go down the group thermal stability increases because the size of the cation increases and the nuclear charge decreases and a result the charge density decreases. This means that the polarizing power decreases down the group with decrease in charge density. As a result the ability of the cation to distort the anion is weak as a result we say that the compunds become more ionic down the group. As a result compounds are more stable thus a large about of energy needs to be supplied to decompose the carbonate or nitrate.
Ahhh okay so more the second one... Thanks so much 👌🏻
0
reply
t
Badges: 13
Rep:
?
#19
Report 4 years ago
#19
I'm really confused about something I've just watched and read. I would like to know, since when can a gas boil? I understand that some gases may be in their liquid state and can therefore boil, but is it ever possible for a gas to boil and how if that is true?
1
reply
Peroxidation
Badges: 15
Rep:
?
#20
Report 4 years ago
#20
(Original post by I <3 WORK)
I'm really confused about something I've just watched and read. I would like to know, since when can a gas boil? I understand that some gases may be in their liquid state and can therefore boil, but is it ever possible for a gas to boil and how if that is true?
Yea that is confusing. I think they're either trying to put something in layman's terms and ruining the science in the process, or they just don't know what they're talking about. There's only really 1 way for liquid to gas changes of state and that's boiling. Obviously there's evaporation too, but that's effectively a controlled surface-only boil. With gases the next highest energy state of matter is plasma, a cloud of gaseous ions. But that's ionisation not boiling.

I suppose if they were talking about a chemical reaction of two gases which produced a visible gaseous product they might've called it 'boiling' in a kind of "it looks like this" way. Or maybe if the reaction produced steam? Either way they've butchered the meaning of the word.
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

Current uni students - are you thinking of dropping out of university?

Yes, I'm seriously considering dropping out (102)
13.42%
I'm not sure (32)
4.21%
No, I'm going to stick it out for now (237)
31.18%
I have already dropped out (18)
2.37%
I'm not a current university student (371)
48.82%

Watched Threads

View All
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