Alright. Sadly, I don't think I have anything in my text I cancrosscheck with for this, so I'm gonna go on vague memories
Umm..and this post may not make sense since you'll just have to suffer through my musings.
So you were given the Molar mass of the salt, when hydrated.
Since otherwise it would just be copper sulfate.
So getting the moles of the hydrated salt shouldn't be difficult.
You just take your initial mass of (CuSO4-5H20) and divide it by the molar mass
Now, if they mean they want the moles of unhydrated salt, you would just use the final dry mass, and divide it by copper sulfate's MM (without the 5H20)
To get the moles of water, you just take initial mass, minus final mass. This difference is obviously the mass of the evapourated water. Divide that mass by the MM of H20 to get the number of moles.
The question is worded strangely. The ratio thing is throwing me (yet, I swear we did something similar when I did it)
The only thing I can think of is that it is *not* 1 mole of CuSO4 for every 5H20.
I would recommend comparing the number of moles of water that you calculated to the number of moles of unhydrated salt you calculated.
I'll keep thinking.....
I don't think I'm making any sense. Sorry
Tell me what you're thinking.