[mgier001]

Hi everyone, I'm new to this forum (this is actually my first post!). I have a question regarding my General Chemistry 1 class lab.  We had a lab where you had to Calculate the H₂0 of Hydration of an unknown substance.  To do this we measured the constant weight of our crucible by removing all of the water from it, and then weighing our unknown and heating it until it became a constant weight as well.  From this we were able to find the weight of the hydrate unknown sample, and the weight of the water lost which gave us the % H₂O of hydration in the unknown.  Unfortunately during my lab when I was heating my unknown, it got burned (quite a bit ).
Nonetheless, to find out what the unknown is, we have to compare our % H₂O of hydration in the unknown to 6 different chemicals (which I will list).  I calculated the % H₂O of hydration for each of the chemicals and I will list them all below:  [by the way: % H₂O of hydration= mass H₂O/total mass]
CuSO₄•5H₂O         36.05%
BaCl₂•2H₂O          14.74%
CoCl₂•6H₂O          45.41%
Na₂CrO₄•10H₂O          52.63%
MnSO₄•H₂O          10.65%
MgSO₄•7H₂O          51.14%

So... when I got my results, my % H₂O of my Unknown was 18.32%.  Fortunately enough, my professor explained to me that because my unknown was burned, I should look up the chemicals that have a % H₂O that were close to my result, and compare the physical properties to those chemicals to find out which my unknown truly is.  (It is extremely important that I figure out which unknown is correct because it is worth 5 points out of the whole 15 point lab! ).  Anyways, I tried to look up Barium Chloride Bihydrate and Manganese Sulfate Hydrate to find their physical properties but I got all confused and could barely find anything.
The physical properties of my unknown are as follows; when I first got the unknown, it was a very very light pink powder.  After heating the unknown and removing the water from the unknown, it looked kind of like a white salt (with a lot of brown because it was burned of course ).
So that's pretty much my big problem, figuring out what my unknown really is.  I hope someone here can help me out!
Thank you so very much in advance to everyone ,
Matt.

[Borek]

I would say you should be able to recognize the substance just knowing the color and the list - only one of them fits the description.

[mgier001]

I would say you should be able to recognize the substance just knowing the color and the list - only one of them fits the description.

This seems to be my problem as I wrote before, I tried looking up the substances given to us (from the list) but I couldn't find out much information at all about them.  Is there any specific website that can help me with this, or any kind of guide on how to read the periodic table (if it gives reference to a chemicals color?)? 

[Borek]

Wikipedia has enough information.

[mgier001]

I was able to find from this website http://avogadro.chem.iastate.edu/MSDS/MnSO4-H2O.htm that the Mn compound is pink, and the Mg compound is white, and from there I determined my answer. Thank you borek.