Water of Crystallisation

Hey guys, I was wondering if you can help me out with some college work. I need to do the following question:

Barium hydroxide exists in the hydrated form of Ba(OH)2.xH2O. A 0.32g sample is weighed out in a weighing boat and transferred to a crucible of known mass. The crucible is of known mass. The crucible is then heated for one minute, allowed to cool for 20 minutes and then weighed. The mass of the solid sample in the crucible is 0.20g.

Calculate the value of x in Ba(OH)2.xH2O

Please can you tell me how the hell to do this. Thanks :)

Goddammit if you guys can't even do it then I got no hope :(

You are an absolute n00b. Is this really college work?

When you heat the crucible, the water of crystallisation is evaporated, therefore m(H2O)evaporated = m(Ba(OH)2.xH2O)

You are an absolute n00b. Is this really college work?

When you heat the crucible, the water of crystallisation is evaporated, therefore
m(H2O)evaporated = m(Ba(OH)2.xH2O)) - m(Ba(OH)2) = 0.32 - 0.20 = 0.12g
n(H2O) = m/Mr = 0.12/(16+2) = 0.0067 mol

Also, m(Ba(OH)2) = 0.20g
n(Ba(OH)2) = m/Mr = 0.20/(171.34) = 0.0012 mol

Find a ratio that matches these two species, let the denominator of n(H2O) be x (because in the equation it is a coefficient).

n(H2O) = x*n(Ba(OH)2)
0.0066 = 0.0011x
x = 5.583 blah blah blah
but since the measurements are inaccurate anyway, x = 6

Thanks, I get it now :)

You explained it better than my professor lol

You are an absolute n00b. Is this really college work?

You are an absolute genius. Is this really elementary work?

Your professor is not an absolute genius, is he an obsolete n00b?

Water crystals are just another form of motion, expanding and growing in cold, melting and flowing in warmth, soaring higher and higher in the heat of the sun to cool, combine, fall, and freeze to be warmed yet again.

>>9
Motion describes a verb, while water crystals are a noun.  How can a noun be a form of a verb?

>>10
You're on the right track, you may want to look into the recently discovered explanations of atoms.
-When you look at an atom, it appears as a particle.
-On paper, it appears as a wave-form.
Atoms are both a noun and a verb...if it is this way with atoms, it is this way with every piece of matter...epic lulz, truly epic.

>>11
This is hilarious. You can't get more troll than this without actually fooling people. I swear there's one person like this on every forum on the internet.

>>12
Ah, I see you can't be fooled. Congratulations on winning the game, and your prize?

http://en.wikipedia.org/wiki/Implicit_memory
Do you fit this bill?

The best way to fool a person is to tell them the truth.
And if that doesn't work, lie.

One girl kicked me in the shin by accident and apologized.
I said, oh, that's okay.
She said, she was sorry again as though she didn't believe me.
So, I said, Fine, apology accepted.
And she said, What?

>>11
80 yrs ago is not recent.
Atoms are a noun, not a verb.

>>15
more recent than the bible, faggot.