Answer:
The molar enthalpy of vaporization in kJ/mol for butane = 24.265 kJ/mol.
Explanation:
n = mass/molar mass = (4.0 g)/(58.12 g/mol) = 0.0688 mol.
∴ 0.0688 mol of butane requires a gain in enthalpy of 1.67 kJ to be evaporized.
Know using cross multiplication:
0.0688 mol of butane to be vaporized requires → 1.67 kJ.
1.0 mol of butane to be vaporized requires → ??? kJ.
∴ 1.0 mol of butane to be vaporized requires = (1.0 mol)(1.67 kJ)/(0.0688 mol) = 24.265 kJ.
∴ The molar enthalpy of vaporization in kJ/mol for butane = 24.265 kJ/mol.