Question

How do I find the formula of the hydrate with this??
Mass of crucible- 19.508g
Mass of hydrate- 20.976g
Mass of dehydrate- 20.447g

Answer 1

the mass of hydrate also includes the mass of the crucible, and so does the mass of the "dry" salt.

#2 - #1 gets you the mass of the hydrate before heating.

#3 - #1 gets you the mass of the "dry" salt

#3 - #2 gets you the mass of water lost by the hydrate

Take the mass of water lost (#3 - #2) and find moles of water lost

Take the mass of "dry" salt (#3 - #1) and find the moles of salt left behind (you need the molar mass of the salt to do this)

Take the ratio moles of water over moles of salt, and you should get a small whole #.