Calculate the energy change during a phase change.

Question

Given the following information for tin, Sn (at 1 atm), calculate the amount of heat in kJ needed (at 1 atm) to melt a 40.6-g sample of solid tin at its normal melting point of 232 °C.

boiling point = 2.27×103 °C	Hvap(2.27×103 °C) = 230 kJ/mol
melting point = 232 °C	Hfus(232 °C) = 7.07 kJ/mol
specific heat liquid = 0.243 J/g°C

_____kJ

Answer 1

q = m∆Hfus

q = heat = ?

m = mass = 40.6 g = 40.6 g x 1 mol/119 g = 0.341 mol

∆Hfus = enthalpy of fusion = 7.07 kJ/mol

q = (0.341 mol)(7.07 kJ/mol)

q = 2.41 kJ