1.Given a 2.785 g sample of NiCl2 . 6 H2O

(a)how many grams of water are there in the sample?

(B)The mass percent of water in the sample is what?

(C)What mass of the given hydrate must be heated to obtain 10.50 g of NiCl2?

2. A student is asked to determine the formula of a hydrate of colbalt (II) chloride. The mass of the empty clean, dry crucible and cover, after heating is 22.446 g. A sample of 0.324 g of cobalt chloride is added to the crucible. After the first heating, the mass of the crucible, cover and dehydrated sample is 22.623 g. After the second heating, the mass of the crucible, cover and sample is 22.622.

(a) the mass of the dehydrated sample is what?

(b)the mass of the water that was driven off is what?

(c)the percent of water in the hydrate is what?

(D)the formula of the hydrate is what?

3.A 1.543 g sample of a mixture of BaCl2 . 2H2O and Nacl as heated until a constant weight had been reached. The dehydrated sample the weighed 1.415g. What is the percent by mass of the hydrate in the mixture?