Covalency and Oxidation Number in Covalent Compounds

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hms.tech
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Homework Statement



[itex]NCl_{3}[/itex]

What is the Co-valency / Oxidation number of Nitrogen in this Covalent compound ?

Homework Equations



I think the table of electronegativity might be useful

The Attempt at a Solution



Nitrogen must be "-3" since it is more electronegative than Chlorine.

The correct answer is +3. How is that possible ?

Clearly Nitrogen is more electronegative than chlorine.
 
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hms.tech said:

Homework Statement



[itex]NCl_{3}[/itex]

What is the Co-valency / Oxidation number of Nitrogen in this Covalent compound ?

Homework Equations



I think the table of electronegativity might be useful

The Attempt at a Solution



Nitrogen must be "-3" since it is more electronegative than Chlorine.

The correct answer is +3. How is that possible ?

Clearly Nitrogen is more electronegative than chlorine.

Chlorine is more electronegative than nitrogen. :)
 
Pranav-Arora said:
Chlorine is more electronegative than nitrogen. :)

Nitrogen forms hydrogen bonds in its compounds with Hydrogen attached .

Chlorine rarely forms any hydrogen bonds in any of its compounds .

Here :
Electronegativity scale.jpg
 
hms.tech said:
Nitrogen forms hydrogen bonds in its compounds with Hydrogen attached .

Chlorine rarely forms any hydrogen bonds in any of its compounds .

Here : View attachment 55758

Allen Scale? :confused:

Pauling Scale is the one you need to use.
 
Pranav-Arora said:
Allen Scale? :confused:

Pauling Scale is the one you need to use.

hmm...doesn't Pauling scale gives us wrong values since according to pauling scale Chlorine being more Electronegative should form Hydrogen bonds .
 
As if it all mattered...

First: oxidation numbers don't reflect any real property of the element, they are used just for electron accounting.

Second: using electronegativity to predict anything is a quite fuzzy concept, more of a general indication than a hard rule, especially when the differences in electronegativity are small.

Taking both things into account - don't be surprised you get inconsistent predictions trying to apply rule of thumb to border cases.