past papers (1 Viewer)

[angelxtearz]

Re: 2005 paper, does anyone noe what q 4 would be?

would anyone happen to have solutions for the 2004 and 2005 past papers?

if you do could u please post em up or pm me

thankyooz

 

[Dreamerish*~]

Would you mind posting the question? I can't access the adobe file at the moment, and it would be more convenient anyway.

There are only solutions to multiple choice questions, and the 2005 solutions aren't out yet. The 2004 solutions can be found here: http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2004exams/pdf_doc/chemistry_er_04.pdf

 

[Riviet]

Re: 2005 paper, does anyone noe what q 4 would be?

I have last year's paper handy with me.
Q4 Firstly, A and C are both wrong because of the H-benzene-H monomer which is totally different to the polymer formed.
Now if we look at choice B's monomer 1, there are two H's missing under the 2 C's; this will not polymerise to form the polymer shown in the question, which has 4 H's linked to the carbons:
hh
| |
c-c-
| |
h h

The reason is because the H's connected to the C's don't move or disappear when a condensation polymer is formed. So the answer is D.

 

[angelxtearz]

ah.

i kind of get it, another q, so during polymerisation, do the monomers still maintain most bonds?

 

[angelxtearz]

and also..

with the 2004 paper,
does anyone get q 11, i thort it would be pentanol, since its the lowest molecular weight isn't it since it has the smallest carbon chain? but according to the answers its hexanol.

 

[Riviet]

i kind of get it, another q, so during polymerisation, do the monomers still maintain most bonds?

There are two main types of polymerisation that you need to know:

Addition- the monomers link together so that all the atoms present in the monomers are also present in the polymer. Monomers must contain contain a double bond for this to be possible. One of the bonds in the double bond is broken and the electrons made available are used to link all the monomers together by single covalent bonds.

Condensation- the funcational group on one monomer reacts with the functional group on another monomer to form water or some other molecule. The electrons made available on the end of each monomer link together by single covalent bonds.

 

[insert-username]

with the 2004 paper,
does anyone get q 11, i thort it would be pentanol, since its the lowest molecular weight isn't it since it has the smallest carbon chain? but according to the answers its hexanol.

The X is at the second spike. The question tells you that the hydrocarbons come out in order of increasing molecular weight - hence, pentanol is the first spike, hexanol is the second, etc.


I_F

 

[pLuvia]

Exactly what he said,

you should becareful of silly mistakes like that