posted by Persia .
Ethane, C2H6 has a molar heat of vaporization of 15 kj/moles. How many kilojoules of energy are required to vaporize 5 grams of Ethane?
Calculate the number of grams in a mole of C2H6, using the chemical formula and the atomic masses of C and H. It will be close to 30 g/mol.
5 g would then be about 5/30 = 1/6 mole.
Multiply the number of moles by the molar heat of vaporization, 15 kJ/mol, for the answer.