Destroyer Gchem #18

[DATkiller]

Advertisement - Members don't see this ad

Can anyone explain why Si-O bond is stronger than the C-C bond?
It saids that silicon is a metaloids and forms a very strong Si-O bond...

 

[americanpierg]

Can anyone explain why Si-O bond is stronger than the C-C bond?
It saids that silicon is a metaloids and forms a very strong Si-O bond...

this is probably one of those stupid borderline trick questions that destroyer has. im assuming it is becuase Si is a metalloid so the Si-O bond may be closer to an ionic bond than a covalent bond, which would be a case by case issue with you having to be familiar with every metalloid/nonmetal bond.

the easier answer might also be that since C-C is obviously a non polar covalent bond, the electronegativity difference between an Si and O molecule must be larger than that of the two carbons and thus be a stronger bond, but this would also have nothing to do with the fact that Si is a metalloid and make the reasoning they gave in the solution irrelevant.

 

[DATkiller]

Thanks for the reply. So you think NaCl has a stronger bond than let's say methane? How come NaCl easily turns into aqoues solution when in water but methane who has weaker bonds doesn't? This has always been a mystery to me lol

I just want to know if an ionic character or polar-covalent character makes a bond stronger or not. This is open for debate...

 

[NewBee12]

HI there

The Si-0 bond is ionic in nature.....the C-C bond is covalent. Since Si and O have different electronegativities, an ionic compound results. This means the bond is stronger.
i hope this helps

 

[Skateguitar]

I am not 100% but i remember something similar like this from chads videos,
maybe someone else can correct me.
There are 3 intermolecular forces; Hydrogen bonds, Dipole Dipole and London Dispersion (Vanderwalls). C-C bonds are Nonpolar, so they fall into the category of London Dispersion Forces.
H bonds > DipoleDipole > London in strength. Ionic Bonds beat ALL OF THESE.
As far as why does nacl dissolve in water and methane not, i am not sure, i just woke up cant think straight 😴

 

[alanan84]

Thanks for the reply. So you think NaCl has a stronger bond than let's say methane? How come NaCl easily turns into aqoues solution when in water but methane who has weaker bonds doesn't? This has always been a mystery to me lol

I just want to know if an ionic character or polar-covalent character makes a bond stronger or not. This is open for debate...

Bond strength is generally tied to differences in electronegativity. The larger the difference in electronegative, the stronger the bond.

NaCl dissolves in water easily because it is polar, like water. (like dissolves like) Methane however is nonpolar.

 

[305602]

For the dissolution of NaCl vs. CH4 question, remember that "like dissolves like"

There is a massive difference in electronegativity between Na+ and Cl- (being that it is an ionic compound)
Methane is completely nonpolar, both because C and H have effectively the same electronegativity but also methane is tetrahedral so any electronegativity would be null and void anyways.
Water is, of course, a polar molecule. So it's not going to dissolve methane

 

[DATkiller]

That's true. But by dissolving I meant this:
NaCl(S)-->Na+ + Cl-. Na and Cl are ionized. Maybe the H bonding between water and NaCl is so strong that it dissociates the bond completely.