How to find out oxidation state when compound has multiple electronegativities How do I solve for oxidation state in something like CH3-O-F? The fluorine is more electronegative than the oxygen which is more electronegative than the carbon which is more electronegative than the hydrogen. In this case would everything except the fluorine be oxidized?
You can assign oxidation states with a method similar to assigning formal charges.


Draw the Lewis structure.
Assign each atom all of its lone pair electrons.
For bonding electrons assign all of the electrons to the more electronegative element.
For each atom perform the following calculation:
number of electrons in the atom in its elemental state - assigned electrons = oxidation state.


In your example, the oxidation number of each $\ce{H}$ is +1 and of $\ce{F}$ is -1.  The oxidation number of $\ce{C}$ is -2 and of $\ce{O}$ is 0.