text: how much heat (in calories) must be applied to a 100 ml beaker filled with boiling water in order to vaporize? well it didn't include all of the question so... how much heat (in calories) must be applied to a 100 ml beaker filled with boiling water in order to vaporize the water? 100 ml of water is 100 gms,   540 calories needed per gm of water turned to steam, so  54,000 calories will convert your 100 ml of boiling water into steam.