In: Chemistry
Calculate the total ionization energy for the formation of C4+ from a gaseous C atom.
Ionization energy for formation of C4+ ion from gaseous C atom = ionization energy to remove the 1st electron + ionization energy required to remove second electron
So,
ionization energy required to remove the 1st electron from gaseous C atom to form C5+ ion (IE1) is given as
deltaE = - 2.18 x 10^-18 * Z^2 [ 1/nf^2 - 1/ni^2 ] for 1st ionization energy nf = infinity and ni = 1
deltaE = - 2.18 x 10^-18 * (6)^2 * [ 1/(infinity)^2 - 1/1]
deltaE = -2.18 x 10^-18 * 36 * (-1) Since 1 / infinity = 0
deltaE = 7.85 x 10^-17 J
Energy per mol = 6.022 x 10^23 mol^-1 * 7.85 x 10^-17 J = 4.727 x 10^5 J/mol = 472.7 kJ/mol
Ionization energy required to remove the 1st electron from gaseous C atom to form C4+ ion (IE2) is given as
deltaE = - 2.18 x 10^-18 * Z^2 * [1/nf^2 - 1/ni^2 ]
deltaE = - 2.18 x 10^-18 * 36 * [ 0 - 1/4] ( ni = 2 and nf = infinity)
deltaE = 1.962 x 10^-17 J
Energy per mol = 6.022 x 10^23 * 1.962 x 10^-17 J/mol = 1.182 x 10^5 J/mol = 118.2 kJ/mol
So total ionization energy = IE1 + IE2 = (472.7 + 118.2) kJ/mol = 590.9 kJ/mol