chemistry
posted by diana on .
A 116.9 g sample of nitric acid solution that is 70.0% HNO3 contains how many moles of HNO3?
how did you get the answer

The sample has a mass of 116.9g. If it is 70% HNO3 (by mass but the post doesn't say that), then the mass of HNO3 is that 116.9 g is 116.9*0.70 = ? grams HNO3.
Then moles HNO3 = grams HNO3/molar mass HNO3.