Posted by **Amy~** on Thursday, August 26, 2010 at 10:36pm.

What would be the steps to solving this problem?

The aluminum sulfate hydrate [Al2(SO4)3 (times) xH2O] contains 8.20 % Al by mass. Calculate x, that is , the number of water molecules associated with each Al2(SO4)3 unit.

- Chemistry -
**MathMate**, Thursday, August 26, 2010 at 11:29pm
RMM for Al2(SO4)3

=27*2+(32+4*16)*3

=342

RMM for H2O

=2+16

=18

Number of water molecules = n

Thus

27*2/(342+18n)=0.082

Solve for n to get 18 (to 2 signinficant digits).

- Chemistry -
**Amy~**, Thursday, August 26, 2010 at 11:43pm
Thank You so much!

I have some other questions that I don't understand.

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