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Help in AS Chemistry!

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The SMA:
guys i need help on answering On
1) O/N 2004 p2, Q1d (i) (ii), Q 2b, Q 4f (ii)
2) O/N 2008 p2, Q2 (ii),

The SMA:
could someone help me pleaase? :)

aldehyde1612:
for 2008 Q2... which part ii...?

The SMA:

--- Quote from: aldehyde1612 on May 29, 2010, 01:30:45 pm ---for 2008 Q2... which part ii...?



--- End quote ---

sorry forgot to state it supposed to be Q2 C (ii).

nid404:

--- Quote from: The SMA on May 29, 2010, 07:48:23 am ---guys i need help on answering On
1) O/N 2004 p2, Q1d (i) (ii), Q 2b, Q 4f (ii)
2) O/N 2008 p2, Q2 (ii)



--- End quote ---

1) nov 04
1) d)i)
ii) bond energy
 HI=299kj/mol
H2=436kj/mol
I2=151kj/mol

Energy for bond breaking= 2 X energy to break HI bond= 2X 299=598 kj
Energy  for bond making = bond energy of H2 + bond energy of I2= 436+151=587kj


2) b) i) Al2O3 has a high melting point because it's an ionic structure held together by strong electrostatic forces of attraction between oppositely charged ions of Al3+ and O2-

ii) SO3 consists of small molecules held together by weak Van der Waals forces. Hence low mp

ii) SiO2 is a giant covalent molecule. it has strong covalent bonds and requires high energy to break them. P4O10 is a simple molecular compound with weak Van Der Waals forces between the molecules.

4) f) ii) apparently a mistake in the ms :/ Very rarely happens but it is definitely a mistake...I've asked my teachers abt it

structure is

   H  H
   |  |
R-C-C -CH2OCOCH3
   |   |
CH3  Br

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