[Jared]

Would you expect that changing the solvent would change the R_f value for a cation such as Zn²⁺.  An explaination  as to why or why not would be helpful as well.

Just a reminder;

R_f = Distance from origin to final position of ion
             Distance from origin to sovlent front

[enahs]

It depends on what you are changing from, and too.

[Jared]

If you mean changing the solvent, it doesnt specify exactly but I'll go with water to something else

[enahs]

Well, then it can either lower or raise Rf, or not change it at all, or you can choose one where the Zn2+ ion will not move with mobile phase. I mean, those are the options.

It all depends on which two you are comparing if the Rf will increase, decrease, not change or not work. It is a poor question.

I guess the answer for how you have the question worded would be "yes", but not always.