The standard enthalpy change for the fusion of 1.5 moles of solid lead Pb to liquid lead at its melting point can be calculated using the molar enthalpy of fusion and the number of moles.Standard enthalpy change H = moles molar enthalpy of fusionH = 1.5 moles 4.79 kJ/molH = 7.185 kJThe standard enthalpy change for the fusion of 1.5 moles of solid lead to liquid lead at its melting point is 7.185 kJ.