Question

The energy released when a mole of neutrons (1.00866 AMU) changes into a mole of protons (1.00728 AMU) is:

a.9.0655x1013kJ

b.9.0655x1016kJ

c.1.240x1014kJ

d.1.240x1011kJ

Answer 1

Mass of one neutron = 1.00866 amu

Mass of one proton = 1.00728 amu

mass consumed = (Mass of one neutron) - (Mass of one proton)

mass consumed = (1.00866 amu) - (1.00728 amu)

mass consumed = 0.00138 amu

mass consumed = 0.00138 amu * (1.66054 x 10^-27 kg / 1 amu)

mass consumed = 2.29 x 10^-30 kg

For 1 mole,

mass consumed = 2.29 x 10^-30 kg * (6.022 x 10²³ atoms/mol)

mass consumed = 1.38 x 10^-6 kg/mol

energy released = (mass consumed) * (speed of light)²

energy released = (1.38 x 10^-6 kg/mol) * (3.0 x 10⁸ m/s)²

energy released = 1.24 x 10¹¹ kJ/mol