IGCSE CHEMISTRY DOUBTS HERE !!!!

[Most UniQue™]

I hope I helped

Attached.

Excuse my drawing skills 

Got it tnxxxx a lot!!!

Anyone cn do 5a(ii) and 5b?

[The Golden Girl =D]

Got it tnxxxx a lot!!!

Anyone cn do 5a(ii) and 5b?

I drew Q.5]b)  but I'm not sure of it as for a)ii) , Ask Fidato to help you out with that one

[Amelia]

Silicon Carbide is like the diamond structure. I hope this gives you the idea.



Dia. 1 - Draw one carbon; surrounded by silicon atoms.

Dia 2 - Draw one silicon atom, surrounded by carbon atoms.

[Most UniQue™]

Silicon Carbide is like the diamond structure. I hope this gives you the idea.



Dia. 1 - Draw one carbon; surrounded by silicon atoms.

Dia 2 - Draw one silicon atom, surrounded by carbon atoms.

should the diagram look exactly the same as diamond or only i need to show the four bonds?

[Amelia]

should the diagram look exactly the same as diamond or only i need to show the four bonds?

Just the four bonds, yes. They are asking you to show only a 'part' of the diamond shape, that's all. 

[Most UniQue™]

Just the four bonds, yes. They are asking you to show only a 'part' of the diamond shape, that's all. 

WHat i mean is that should they be in the same positions or they can be random positions?

[Amelia]

WHat i mean is that should they be in the same positions or they can be random positions?

Oh that! Yeah, you can draw any way you want.

[Most UniQue™]

Oh that! Yeah, you can draw any way you want.

Oh ok tnxxx a lot!!

[Assi1993]

heelloo frieds can anyone pleasseeeeee solve this question today?? its urgent..

8.   A gaseous organic compound, X, was burnt in an excess of oxygen. A 0.112 dm  sample of X, measured at s.t.p., produced 0.88 g of carbon dioxide.
How many carbon atoms are there in one molecule of X?
 waiting
thankuuuu SF

[~ Miss Relina ~]

heelloo frieds can anyone pleasseeeeee solve this question today?? its urgent..

8.   A gaseous organic compound, X, was burnt in an excess of oxygen. A 0.112 dm  sample of X, measured at s.t.p., produced 0.88 g of carbon dioxide.
How many carbon atoms are there in one molecule of X?
 waiting
thankuuuu SF

I am not pretty sure but I'll try
0.88/44 = gives the no.of mole of CO₂= 0.02
0.02 x 12 = give no.ofmoles of carbon atoms present= 0.24
multipy 0.24 by avogaro's constant 6.023*10²³=1.45*10²³
 I Hope I helped

[Romeesa-Chan]

heelloo frieds can anyone pleasseeeeee solve this question today?? its urgent..

8.   A gaseous organic compound, X, was burnt in an excess of oxygen. A 0.112 dm  sample of X, measured at s.t.p., produced 0.88 g of carbon dioxide.
How many carbon atoms are there in one molecule of X?
 waiting
thankuuuu SF

Shouldn't this be in the A-level section ?

[~ Miss Relina ~]

inQ 4 F (ii) here http://www.xtremepapers.com/CIE/Cambridge%20IGCSE/0620%20-%20Chemistry/0620_w06_qp_6.pdf


I would like to know why it is drawn below zinc ones instead of being below the magnesuim powder one

plz soooon reply

[NotAbod]

Zinc is more reactive than iron, Magnesium is more reactive than both.

Reactivity series, here is how you learn it:

K   Kitten
Na   not
Ca   Cat
Mg   make
Al   a
Zn   Zoo
Fe   For
Pb   Poor
H2   Hungry
Cu   Childeren
Ag   (and these too just learn them silver comes first and then gold)
Au   

So the sentence is: kitten not cat, make a zoo for poor hungry children, silver and then gold.


Learn the reactivity series, it will help you.

[Arthur Bon Zavi]

Zinc is more reactive than iron, Magnesium is more reactive than both.

Reactivity series, here is how you learn it:

K   Kitten
Na   not
Ca   Cat
Mg   make
Al   a
Zn   Zoo
Fe   For
Pb   Poor
H2   Hungry
Cu   Childeren
Ag   (and these too just learn them silver comes first and then gold)
Au   

So the sentence is: kitten not cat, make a zoo for poor hungry children, silver and then gold.


Learn the reactivity series, it will help you.

The reactivity series is given in data booklet in the form of  standard reduction potentials.