Chemistry Paper 2 discussion =)

[Pals_1010]

Hey member,

Your answer sounds good. I wrote approx. the same thing.

For the first part,

1) In graphite, the carbon atoms are arranged in layers and in hexagonals while in diamond, the arrangement of carbon atoms form a tetrahedral structure.

2) In diamond, one carbon atom is covalently bonded to four other carbon atoms while in graphite, one carbon atom is covalently bonded to three other carbon atoms

For the second part.

In diamond, there are numerous strong covalent bonds in a giant three dimensional structure and that makes diamond very hard. But in graphite, there are weak Van Der Waal's forces of attraction betweeen the layers of atoms and the layers of atoms can easily slide over one another, making graphite soft and slippery.

Hope we got it right!!!

Anyone else got an idea?

 

[Prince III]

Pals your answer is Perfect

 

[member]

differnces between graphite and diamond

1. graphite structure is such that carbon atoms are bonded in hexagonal ring in layers while in diamond there are no layers .
2.in dimond each carbon atom is bonded with 4 carbon atons with a bond angle of 109.5 , but in graphite this is not the case

why graphite is soft ?
was this the question or it was
why graphite is soft but diamond hard ?

i just wrote in graphite carbon atoms are bonded in hexagonal ring in layers which slips over eachother when force is exerted while in diamond there are no layer which would slip upoun eachother


Please anybody respond

Pal and prince is my answer wrong for the second question ?
i have mentioned why graphite is soft but not mentioned that why diamond is hard

or the question was only to tell why graphite is soft ???
please tell me PALS and prince III

 

[member]

for the conditions in second question(organic) i wrote
1.temperature moderatly high
2. if concentration of reactants is increased

would that be correct ?

 

[member]

please respond me i beg you i m hell worried about these questions

 

[Pals_1010]

Take a breather member... Chillax.

I dont think u will lose marks. Because in part (a) u already stated that there is a layered arrangement in graphite and not diamond. So when u answered in part (b) why graphite is soft u talked about the layers. So it more or less implies that this doesnt occur in diamond and that why diamond is hard...

so relax..

and hey was carbon monoxide in our syllabus??? Because the structure involved dative bonding!!! any idea?

Thx Prince

 

[member]

for the conditions in second question(organic) i wrote
1.temperature moderatly high
2. if concentration of reactants is increased

would that be correct ?

thanks PALS for support and would this be also acceptable ?

 

[Prince III]

and hey was carbon monoxide in our syllabus??? Because the structure involved dative bonding!!! any idea?

Thx Prince

yes you are right this was out of sylabuss because this is quite advance bonding known as dative covalent bonding

But i have askhed one of chemistry sir , he said that examiner would be looking for just " tripple covalent bond" to give full marks
so basically , this question was to test that is a candidate able to draw a tripple covalent bond and does he / she know that in tripple covalent bond 6 electrons are shared

so we just have to share 6 electrons between them and the rest of electrons still revolving in the shells

see the below diagram
this would be accepted

 

[Pals_1010]

The temperature is correct.

Am not too sure for the concentration. That would increase the rate.

 

[Pals_1010]

Thx Prince. I was having a panic attack during the exams because of that haha..

But the rest was plain sailing... Next is paper 4...

 

[Heshna]

can someone please send me some notes on electrolysis...please... my e-mail address is [email protected]..thanks in advance

 

[Prince III]

can anybody tell the questions & answers of complete question number 1 from section A (paper22)

1. name the metal which forms alkaline solution in water
A. pottasium (k) fisrt group metals are called alkali metals

2.name the metal which forms oxide layer
A . aluminium

3.name a metal which rust it self to protect the other metal from rusting
A . magnisium

4.name a metal from period V
A.silver (Ag)

this is all i could remember


(b) structure of typical metal and labeling

 

[Prince III]

can someone please send me some notes on electrolysis...please... my e-mail address is [email protected]..thanks in advance

i have notes
i would upload them overhere so that it could be helpfull to others aswell !

 

[Prince III]

hope they are helpfull

and guys come back to discussion

 

[carolinetcw]

can anybody tell the questions & answers of complete question number 1 from section A (paper22)

1. name the metal which forms alkaline solution in water
A. pottasium (k) fisrt group metals are called alkali metals

2.name the metal which forms oxide layer
A . aluminium

3.name a metal which rust it self to protect the other metal from rusting
A . magnisium

4.name a metal from period V
A.silver (Ag)

this is all i could remember


(b) structure of typical metal and labeling

i wrote magnesium for the alkaline one. Mg reacts with H2O to form Mg(OH)2 which is also alkaline as its a hydroxide,right? I hesitated to use potassium cause i thought reaction wud be explosive,lol.

 

[Zeuss]

The very last question.
SO2 + O2 <==> SO3
What is the effect of increase in temperature?
(I forgot the exact question).
I said that more SO2 and O2 will be produced.
Is that correct?

 

[Pals_1010]

The question, I think, was "What is the effect on the equilibrium when temperature is increased?"

According to Le Chatelier's Principle, dynamic equilibrium shifts backwards to decrease the temperature as the backward reaction is endothermic.
Thus, the yield of SO3 decreases and that of O2 and SO2 increases.

 

[Heshna]

what are the chapters we might be having for paper 4 ????

 

[Pals_1010]

Salt analysis, Calculations, Titration, Identification of gases, Redox reactions. These are the recurring paper 4 questions

 

[Heshna]

thanks pals_1010