Answer :
The question is confusing, but if you are saying that the heat of vaporization is 393 joules per gram, and 30 grams condense, then the answer is simply 30 * 393 = 11790 joules.
The question is confusing, but if you are saying that the heat of vaporization is 393 joules per gram, and 30 grams condense, then the answer is simply 30 * 393 = 11790 joules.