How is your preperation for Chem Unit 2 ???

[Shoggaine]

Haha...i knw how much u knw abt KSA

 

[DANGERBP]

For group 1 : The carbonates do not decompose. Only nitrates decompose to nitrites and oxygen except Li.
For group 2 : The carbonates decompose to form its oxide and carbondioxide.
The nitrates decompose to form its oxide, nitrogen dioxide and oxygen. Li acts as same way as Grp 2.

ya i got that thank you !
but how would we know whats the most stable metal carbonate ??

 

[étudiante]

haha hey ! =p thanks allot !
umm hey would you happen to know how to find most ionic characters bet elements n most covalents ones ??

ur welcome
are u asking about the electronegativity thingy?

 

[DANGERBP]

nd bout chemistry wat points do we exactly need to know =$ i havent touched that part yet ! =p

 

[étudiante]

Haha...i knw how much u knw abt KSA

challey my bro lives dere

 

[DANGERBP]

ur welcome
are u asking about the electronegativity thingy?

umm i dono actually ? do we look for electronegativity or the size of the atoms ? =$

 

[étudiante]

nd bout chemistry wat points do we exactly need to know =$ i havent touched that part yet ! =p

which chemistry? Green Chem?

 

[xIshtar]

ur welcome
are u asking about the electronegativity thingy?

I think he was.

And a quick question for anyone
Uhh, when we talk about thermal stability of carbonates and nitrates, can we describe it in terms of polarising power? Or do they prefer if we talk about the energy released when the ions come together to form the oxide and carbon dioxide?
Or maybe I should write both

Thanks in advance xD

 

[Shoggaine]

The thermal stability increases down da group which means the ease of decomposition decrease. For eg in gp 2 Barium carbonate will take more time to decompose than calcium carbonate.

 

[étudiante]

umm i dono actually ? do we look for electronegativity or the size of the atoms ? =$

m still not sure wat ur asking sorry

are u talking abt the ionic character in covalent bonds? den for that we see electronegaitivity difference between the two atoms in the bond

 

[étudiante]

I think he was.

And a quick question for anyone
Uhh, when we talk about thermal stability of carbonates and nitrates, can we describe it in terms of polarising power? Or do they prefer if we talk about the energy released when the ions come together to form the oxide and carbon dioxide?
Or maybe I should write both

Thanks in advance xD

Polarising power is the better option

 

[xIshtar]

Polarising power is the better option

Thanks, I think I can explain that better to be honest

 

[Shoggaine]

I think he was.

And a quick question for anyone
Uhh, when we talk about thermal stability of carbonates and nitrates, can we describe it in terms of polarising power? Or do they prefer if we talk about the energy released when the ions come together to form the oxide and carbon dioxide?
Or maybe I should write both

Thanks in advance xD

We have to describe it in terms of polarization nd electronegativity.

 

[étudiante]

Thanks, I think I can explain that better to be honest

Ur welcome np

 

[DANGERBP]

The thermal stability increases down da group which means the ease of decomposition decrease. For eg in gp 2 Barium carbonate will take more time to decompose than calcium carbonate.

wat would be the explanation for this increase in stability ?? n that will increase the lattice energy ya ?makin it more -ve? =$
mm ugh n is it related to solubility too ? =$

m still not sure wat ur asking sorry

are u talking abt the ionic character in covalent bonds? den for that we see electronegaitivity difference between the two atoms in the bond

nd a covalent charecter n n ionic bond wed look for the size of both ions and cations r8 ?

 

[étudiante]

nd a covalent charecter n n ionic bond wed look for the size of both ions and cations r8 ?

partly yes, but we need to see the difference in electronegativity as well, but yes dat is also needed

 

[Shoggaine]

Irum....can u please explain this to her?? I cannot explain :S

 

[étudiante]

Irum....can u please explain this to her?? I cannot explain :S

kya samjhaoon?

 

[Shoggaine]

i think becz it becmz less polarizable nd more ionic down the group. So more forces of attraction and less weakening of C-O nd C-N bond so thermal stability increases down the group.

 

[étudiante]

i think becz it becmz less polarizable nd more ionic down the group. So more forces of attraction and less weakening of C-O nd C-N bond so thermal stability increases down the group.

The size of the lattice enthalpy is governed by several factors, one of which is the distance between the centres of the positive and negative ions in the lattice. Forces of attraction are greatest if the distances between the ions are small. If the attractions are large, then a lot of energy will have to be used to separate the ions - the lattice enthalpy will be large.

The lattice enthalpies of both carbonates and oxides fall as you go down the Group because the positive ions are getting bigger. The inter-ionic distances are increasing and so the attractions become weaker.