Hello,

I have to find which one has the shortest length to the longest. I think it's O, N, M. 

>hybridization is the same

>atom size is the same

>electronegativity is the same

>charge is the same

------------ O has about 7 resonance structures, N has about 2 resonance structures, M has about 7.n

I'm not sure how much induction is a factor if at all because they are too far away. 

The smaller pKa has the most stable conjugate base. 

I dont understand what the OCH3 and OCCH3 do to the groups. 

any help is appreciated 

update: turns out we haven't covered this in class and it won't be on exam one lol, but I did find O has a has an electron withdrawing group while M has an electron donating group. O's group stabilizes the molecule rather than M's group that donates so it is less stable than O. 

I would draw out the resonance forms of M in the conjugate base form.