# chemistry

posted by .

Calculate the following:
(a) mass of water in the hydrate sample (g):
(b) number of moles of water in the sample:
(c) mass of pure salt in the sample (g):
(d) number of moles of salt in the sample:
(e) molar ratio of water to salt in the sample:

If the mass of the empty crucible (g): 53.200 and the mass of the crucible and hydrate (g): 58.200 and the mass of the crucible and pure salt (g): 56.396

• chemistry -

I must guess what you did since you didn't post it. I assume
56.396 = mass xble + salt
-53.200 = mass empty xble
--------------
3.196 g = mass salt

58.200 = mass xble + hydrate
-53.200 = mass empty xble
---------
5.000 g = mass hydrate

5.000 = mass hydrate
-3.196 = mass salt
---------
1.804 g = mass water added to salt.
a) 1.804 g
b) moles = grams/molar mass
c) see above
d) It would have helped if you had given a little more information like what you were doing and the name of the salt. moles salt = grams/molar mass
e) Not enough information provided. You want to find the ratio of moles salt (d) to moles H2O(b)

• chemistry -

Thank you I been trying to really get the first three I think I figured out the rest through your help thanks.