An aqueous solution labelled 35.0% w/w HClO4 has a density of 1.251 g cm¯3. What is the molarity of the solution?

My first answer was 7.96, the i did it two more times and got 4.23 as another answer and 4.38 as another answer too. I'm really confused on how to do this any help is appreciated thanks

3 answers

a liter of the solution has a mass of 1251 g

35% of the mass is HClO4 ... 1251 * .35 = ?

how many moles is this?
... mass HClO4 / molar mass HClO4
I don't know
I4.378