Chemistry Compare the Bond lengths of IO2F2 and IOF3

[Navin]

Homework Statement

Compare the average bondlengths of the following compounds

IO2F2 and IOF3

Relevant Equations

Bent rules

%S charecter inversly proportional to bond lenth

Okay So our Chemistry Professor gave us the answer as the following

IO₂F₂ has a larger bond length than IOF₃

The reason being is once you draw the structures of the compounds IO₂F₂ has more number of double bonds that the later hence it shall have more p charecter than IOF₃...hence it will have a larger avg bond length...but well i sort of don't undestand this logic

Well hear me out, so a single bond is larger than a double bond right, so IOF₃
Has 3 single bonds, a lone pair and a double bond while IO₂F₂ has 2 single , 2 double bonds , and a lone pair...so due to the latger no of single bonds the avg bond length will be higher in IOF₃

Yea so i think the answer is IOF₃ has the larger avg bond length.(as opposed to my professor)

Could you please rectify me if I am wrong ?
Thank you :)

 

[mjc123]

IO₂F₂ doesn't exist. Do you mean IO₂F₂^-?

Do you mean average length of all bonds, I-O and I-F? That doesn't seem to be a very meaningful comparison.

 

[Navin]

IO₂F₂ doesn't exist. Do you mean IO₂F₂^-?

Do you mean average length of all bonds, I-O and I-F? That doesn't seem to be a very meaningful comparison.

The question was just compare average bond lengths. They didnt specify which bonds to compare

And yes, I am sorry the copound was IO₂F₂^-
Im so sorry for that error

 

[Navin]

EDIT#1 - THe Question is to compare Average bond lengths of IO₂F₂^- and IOF₃There is an error in the Orignal post where i forgot to add the "-" superscript, sorry for the inconvinience

 

[mjc123]

I think you'd have too many electrons round I if you had two I=O double bonds in IO₂F₂^-. In IOF₃, replace one F by O^- (with a single bond). The IO₂ moiety should be O=I-O^- ↔ O^--I=O (not linear!)

 

[Navin]

I think you'd have too many electrons round I if you had two I=O double bonds in IO₂F₂^-. In IOF₃, replace one F by O^- (with a single bond). The IO₂ moiety should be O=I-O^- ↔ O^--I=O (not linear!)

I agree with this, but they gave the structure like that in the question.
(Im beginning to think this is a horribly framed question...Good job publishers ! Making us students life easier)