A250 gram sample of water at the boiling point had 24.0 kj of heat added. how many grams of water were vaporized? heat of vaporization for water is 40.6 kj/mole.

Let us compute for the total moles that can be vaporized:

moles vaporized = 24 kJ / 40.6 kJ/mol

moles vaporized = 0.59 mol

 

The molar mass of water is 18 g/mol so the mass vaporized is:

mass vaporized = 0.59 * 18 = 10.64 grams

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.