Determine the ionization energy of a hydrogen atom (in kJ/mol) if the electron is in its ground state

It's calculable using the Bohr atomic model or quantum mechanics, but you might as well look it up or use the fact that it is 13.6 eV per atom. Multiply that by the number of atoms in a mole (6.02*10^23) and the number of Joules in an eV (1.602*10^-19). You get 1.312*10^6 J/mol = 1.312*10^3 kJ/mol