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National 5 Chemistry

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Original post by Lewis H01
If the chain is just carbon atoms then it's formed by addition polymerisation
If the chain has other types of atoms (eg. Carbon and nitrogen) then it's formed by condensation polymerisation...


So if the chain was

C-C-C-C-C

Then it would be addition

But if it were

C-C-C-C-O-H

Then it's condensation?
Reply 181
Original post by SocialStudiesETC
Yeah, so if the question was something like "Which type of polymerisation is this?" How would you find out?


They will usually give you a diagram of the structure and they'll ask you to identify what ype of polymerisation is it. The way I like to remember it is this:

Condensation polymers will have di-ols and di-acids (This if for national 5 anyway). The monomers for these will have more than one functional group (usually COOH and OH).

Addition polymers will have Monomers which are UNSATURATED! So it will have double bonds.
(edited 7 years ago)
Reply 182
Original post by Ethan100
Correct me if I am wrong anyone

For addition Polymerisation, I would recognise that the functional group of the monomer is the double bond.

For the condensation Polymerisation, I would recognise that there is an Oxygen atom ( I usually see its a carboxyl group and Hydroxyl group, they take a OH from the carboxyl group and H from alcohol to form water)

I am not 100% sure but If a question like that came up that's how I will tackle it !


Yes this is right
Original post by SocialStudiesETC
So if the chain was

C-C-C-C-C

Then it would be addition

But if it were

C-C-C-C-O-H

Then it's condensation?


Yeah that's how I remember it...:smile:
Is iron the catalyst used in the Haber Process or is it Platinum ?

It says the haber process is a reversible reaction ? In terms of reactions what does reversible mean ?
(edited 7 years ago)
Reply 185
Original post by Ethan100
Is iron the catalyst used in the Haber Process or is it Platinum ?


Iron = Haber
Platinum = Ostwald
Original post by Ethan100
Is iron the catalyst used in the Haber Process or is it Platinum ?


Here is a tip for learning the Haber and Ostwald process...:smile:

Haber
Aluminium
Iron catalyst
Rerversible reaction

Ostwald
Platinum catalyst
Exothermic reaction
Nitric acid
Original post by Lewis H01
Here is a tip for learning the Haber and Ostwald process...:smile:

Haber
Aluminium
Iron catalyst
Rerversible reaction

Ostwald
Platinum catalyst
Exothermic reaction
Nitric acid


Thanks so much :biggrin:

So the Haber process is to make Ammonia and Ostwald Process is to make Nitric Acid.

To make fertilisers, Ammonia + Nitric Acid ------> Ammonium Nitrate

So it can be different types of acids right? to make fertilisers

Ammonia + Sulfuric Acid -----> Ammonium Sulfate

??
Thanks once again
Original post by Ethan100
Thanks so much :biggrin:

So the Haber process is to make Ammonia and Ostwald Process is to make Nitric Acid.

To make fertilisers, Ammonia + Nitric Acid ------> Ammonium Nitrate

So it can be different types of acids right? to make fertilisers

Ammonia + Sulfuric Acid -----> Ammonium Sulfate

??

Thanks once again


Yeah that's correct and you're welcome...:smile:
Any other questions, make sure to ask them...
Hey guys what is the best way to revise all the topics in a short time? Ive left it so late :frown:
Reply 190
Original post by Aston177
Hey guys what is the best way to revise all the topics in a short time? Ive left it so late :frown:


I recommend you go on bbc bitesize.
Just a general question, which topic out of the 3 do you enjoy the most ? I'm just curious ... I would probably say Nature's Chemistry for me
Original post by Ethan100
Just a general question, which topic out of the 3 do you enjoy the most ? I'm just curious ... I would probably say Nature's Chemistry for me


I'm good at all units, but I enjoy unit 2 the most as it's very easy to learn with all the calculations etc. I just find unit 3 boring. :smile:
Should i just read bitesize or take notes aswell?
Original post by Aston177
Should i just read bitesize or take notes aswell?


Yeah I would do that, I would focus on the areas you find difficult because you won't have enough time to look at everything in detail. Look at the sections where you can pick up a lot of marks.
Reply 195
Original post by Ethan100
Just a general question, which topic out of the 3 do you enjoy the most ? I'm just curious ... I would probably say Nature's Chemistry for me


Unit 2 Natures chemistry.

Original post by Aston177
Should i just read bitesize or take notes aswell?


It's up to you. Only read the important stuff.
Original post by Ethan100
Yeah I would do that, I would focus on the areas you find difficult because you won't have enough time to look at everything in detail. Look at the sections where you can pick up a lot of marks.


Like what?
Another question i would like to ask is just say i get 15 marks in my assignment and 15 marks in my multiple choice how many more marks would i need to pass?
What did everyone get in their chemistry prelims?
I got 65 out of 80 (81%) although I rue those silly marks lost...
Original post by Aston177
Another question i would like to ask is just say i get 15 marks in my assignment and 15 marks in my multiple choice how many more marks would i need to pass?


If you get 15/20 in section 1 and 15/20 in Assignment, that's 30% overall. Last year, for a C grade it was 48 percent so If you got 20/60 in section 2, then you would get 50% overall.

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