Ans. Given, enthalpy of fusion of titanium =
20.9 kJ, that is 1 mol titanium requires 20.9 kJ energy to change
its physical forms from solid to liquid state, i.e. melting.
Now,   Â
          Â
20.9 kJ energy melts 1 mol titanium
          Â
Or, 1 kJ
-Â Â Â Â Â Â Â Â Â Â
-Â Â Â Â (1 mol / 20.9 kJ)
          Â
58.0 kJ
-Â Â Â Â Â Â Â Â Â Â
-Â Â Â Â Â Â 1 mol / 20.9 kJ) x 58.0
kJ
                                              Â
= 2.775 moles Ti
Mass of 2.775 moles titanium = Moles x atomic mass
                                              Â
= 2.775 moles x (47.867 g mol-1)
                                              Â
= 132.830925 g
                                              Â
= 132.83 g
Thus, 58.0 kJ energy melts 132.83 g titanium
metal.