Question

Energy of an electron in the ground state of the hydrogen atom is −2.18 × 10⁻¹⁸ J. Calculate the ionisation enthalpy of atomic hydrogen in terms of kJ mol⁻¹.

Answer 1

Energy of an electron in the ground state of the hydrogen atom = −2.18 × 10⁻¹⁸ J

\[\ce{H -> H^+ + e^-}\]

The energy required to ionize 1 mole of hydrogen atoms, we multiply by the Avogadro constant.

E = 2.18 × 10⁻¹⁸ × 6.023 × 10²³

= 13.123 × 10⁵ J mol⁻¹

I.E = +1312 K J mol⁻¹