chem p4 october november 2002 solved most (i need help wid some hehe) XP

[22shimmer22girly]

hey guys im posting the paper plus mark scheme plus my work ... please help me wid some questions ...

 

[22shimmer22girly]

Q1c, 2c and d, 5d, 6cii, 6div,

 

[22shimmer22girly]

Paper 12 heheh forgot it

 

[SadiaMaryam]

Q1 (a) you mentioned only the concentration but we have also to mention what this thing is. I wrote 1.0 mol/dm3 electrolyte (mine is also wrong)
Mark Scheme says 1.0 mol/dm3 H^+ ions or HCL, H2SO4 or any other "named" electrolyte
Q3 (a) (ii) also, 'Si and Ge have weaker bonds than Carbon' (and that is because C-C bond is the strongest of them all) , hence decreasing melting point from C to Ge, although the three have giant molecular structures.
Q4 (a) "Transition elements are heavier and smaller, making them more denser"..we have to mention the heaviness of transition elements along with associated size. Ca atoms are also heavier but they are larger so their mass spreads on that larger volume but transition elements' is a bit squeezed up, making them denser.
Q1 (c) u put a question mark there, probably need some explanation..hun? right..? ..Electrode potential increases because an equilibrium exists between Fe+3 and Fe+2 ions (Fe+3 on the right side and Fe+2 on the left side of the equation), increasing concentration of Fe+3 would shift the equilibrium position to the right, rate of forward reaction will increase, hence increasing electrode potential (more positive)
Increasing Fe+2 concentration will shift the equilibrium to the left, increasing production of Fe+3, which means increasing the rate of reverse reaction, hence electrode potential will decrease (get more negative)
Q2 (d) (i) Sodium forms ions with a charge of +1 while Magnesium forms ions with charge of +2. The greater the charge,the greater is the electrostatic attraction between ions, hence double charged ions form more stronger ionic bonds than those in NaCl (requiring more energy, definitely increasing the magnitude)
(d) (ii) Strong bonding relates to very high melting and boiling points, they can withstand very high temperatures, so can be used in furnace linings as refractory or as fire-resistant materials

I'll discuss Q5 and Q6 tomorrow, too sleepy to think the frowning organic chemistry.
what about paper 5?
and June 2003 paper 4 for tomorrow, right?

 

[22shimmer22girly]

Q1 (a) you mentioned only the concentration but we have also to mention what this thing is. I wrote 1.0 mol/dm3 electrolyte (mine is also wrong)
Mark Scheme says 1.0 mol/dm3 H^+ ions or HCL, H2SO4 or any other "named" electrolyte
Q3 (a) (ii) also, 'Si and Ge have weaker bonds than Carbon' (and that is because C-C bond is the strongest of them all) , hence decreasing melting point from C to Ge, although the three have giant molecular structures.
Q4 (a) "Transition elements are heavier and smaller, making them more denser"..we have to mention the heaviness of transition elements along with associated size. Ca atoms are also heavier but they are larger so their mass spreads on that larger volume but transition elements' is a bit squeezed up, making them denser.
Q1 (c) u put a question mark there, probably need some explanation..hun? right..? ..Electrode potential increases because an equilibrium exists between Fe+3 and Fe+2 ions (Fe+3 on the right side and Fe+2 on the left side of the equation), increasing concentration of Fe+3 would shift the equilibrium position to the right, rate of forward reaction will increase, hence increasing electrode potential (more positive)
Increasing Fe+2 concentration will shift the equilibrium to the left, increasing production of Fe+3, which means increasing the rate of reverse reaction, hence electrode potential will decrease (get more negative)
Q2 (d) (i) Sodium forms ions with a charge of +1 while Magnesium forms ions with charge of +2. The greater the charge,the greater is the electrostatic attraction between ions, hence double charged ions form more stronger ionic bonds than those in NaCl (requiring more energy, definitely increasing the magnitude)
(d) (ii) Strong bonding relates to very high melting and boiling points, they can withstand very high temperatures, so can be used in furnace linings as refractory or as fire-resistant materials

I'll discuss Q5 and Q6 tomorrow, too sleepy to think the frowning organic chemistry.
what about paper 5?
and June 2003 paper 4 for tomorrow, right?

Heyyyyy sweeetooooo thank you sooooo muchhhh for solving the paper and helping me out...btw I have made the necessary corrections in mine thank uuuu...btw I needed help with q2c....I have no idea how to solve it...plus the book doesn't mention it either

Yes u can explain q5 &6 later.....yes for p5 November 2002... We can't do question 1 as its practical right?.... And I need help wid q2.... I know the general ideas but how do I organise it in a chronological way to get the full marks? ....please help ...


Btwyupp I'm solving p4 June 3 and November 3 for chem and phy isA today and I will be posting soon isA

 

[22shimmer22girly]

Question 2 c solved hope it helps

 

[SadiaMaryam]

Question 2 c solved hope it helps

brilliant.!..

 

[22shimmer22girly]

brilliant.!..

Awwwww thAnk you sweeto r u sure it helped? I had been crying for a whole daysdays

 

[SadiaMaryam]

Awwwww thAnk you sweeto r u sure it helped? I had been crying for a whole daysdays

yup..cocksure..I've also understood it now although it was just a hell for me

 

[SadiaMaryam]

Awwwww thAnk you sweeto r u sure it helped? I had been crying for a whole daysdays

which chemistry book do u have? I have "Cambridge International AS and A level Chemistry coursebook by Roger Norris, Lowrie Ryan and David Acaster"

 

[22shimmer22girly]

yup..cocksure..I've also understood it now although it was just a hell for me

Yaaaaaayy but alahamdulilah we solved it...btw when u have time please help in question 5 and 6....I need help in nov 04 p5 ....imma post June 04 tomorrow isA

 

[22shimmer22girly]

which chemistry book do u have? I have "Cambridge International AS and A level Chemistry coursebook by Roger Norris, Lowrie Ryan and David Acaster"

Yes u can check out the various page numbers

 

[22shimmer22girly]

Yupp that's the one I have too...it's the only one I use

which chemistry book do u have? I have "Cambridge International AS and A level Chemistry coursebook by Roger Norris, Lowrie Ryan and David Acaster"

 

[SadiaMaryam]

Yupp that's the one I have too...it's the only one I use

what happened sister? did u solve any other paper? But I could not find Nov 2003 papers on internet..Did u get them?

 

[22shimmer22girly]

what happened sister? did u solve any other paper? But I could not find Nov 2003 papers on internet..Did u get them?

hey sorry no wifi these days so couldnt post them...yupp i have em...should i email them to u?