Your procedure seems generally right, although I didn't check for math or unit errors. In this regard it helps to write out all the units in each step. Also, I'm not sure what "(1/0)" is supposed to be. I assume you mean "(1/∞)", but be careful with this kind of stuff. Also you should specify where the term -4.34x10-18 is coming from.
For the last part you need to solve, here is a hint: your answer to the first part is the amount of energy to remove a single electron from a single hydrogen atom. You need to know how much energy is required to remove a mole of electrons from a mole of hydrogen atoms. How do you do this?