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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Qwertyqwerty on October 04, 2011, 02:27:10 AM

Title: Ionic bond strength
Post by: Qwertyqwerty on October 04, 2011, 02:27:10 AM

What are the factors that determine the strength of an Ionic bond?
Taking the example of LiF and K₂0, why does LiF have a stronger bond strength?

Title: Re: Ionic bond strength
Post by: PaintYourFuture on October 06, 2011, 04:34:02 AM

Electronegativity

Title: Re: Ionic bond strength
Post by: jp92celtic on October 06, 2011, 11:26:07 AM

look at a table of electronegativity values and calculate the difference between your two atoms

Title: Re: Ionic bond strength
Post by: Qwertyqwerty on October 07, 2011, 07:31:27 AM

Isn't there a way to find it out without looking at the electronegativity table? Some general rules one might follow?

The question I had was :
Arrange the bonds in order of the increasing ionic character of the molecules :
LiF, K₂O, SO₂, N₂ and ClF₃

Of which the answer was
N₂<SO₂<ClF₃<LiF<K₂O

I can't understand as to why K₂O has a stronger ionic character than LiF.

Title: Re: Ionic bond strength
Post by: jp92celtic on October 07, 2011, 05:55:50 PM

as a general rule, looking at the periodic table can help:
N₂ obviously has equal EN values, and shares perfectly equally (covalent)
SO₂ has S and O which are both in the same column, one above the other, so they are relatively close in EN.
ClF₃ has the same situation as above but are to the right (more EN)
LiF are hugely separated left to right, but are in the same row as each other.
K₂O is also separated a lot left to right, but K is two whole rows below O, so therefore it has the greatest difference in EN.

Title: Re: Ionic bond strength
Post by: Qwertyqwerty on October 08, 2011, 02:09:18 AM

Finally understood. Thank you  :)