Stechionometry and baic equations

[Ineedhelp.jpeg]

Okay, before you go "this topic already exists" on me- I'm in a rush (my username) and don't really have the time. If someone's good with chemistry (nothing advanced) I really need some help so I can understand some of this for an exam.

One of exam questions I just can't do is: Find the formula of a crystalohydrate FeSO4 that contains 6.3 grams of H20?

[studiot]

5 hours ago, Ineedhelp.jpeg said:

I'm in a rush (my username) and don't really have the time

 

In so much of a rush that you can't be bothered to write the question out properly, let alone follow the help rules and tell us what you have done so far.