how do I set this problem up?….Calculate the heat of vaporization of an unknown substance “X” if 25 grams of “X” absorbs 1250 calories of heat when changing from a liquid to a gas. Given: The molar mass of “X” is 100g/mol.

how do I set this problem up?….Calculate the heat of vaporization of an unknown substance “X” if 25 grams of “X” absorbs 1250 calories of heat when changing from a liquid to a gas. Given: The molar mass of “X” is 100g/mol.