How to determine:

1) Mass of BaCl2.XH2O?

2) Mass of barium chloride anhydrous?

3) Mass of water in BaCl2.XH2O?

4) Percent composition of water in BaCl2.xH2O?

5) Formula of barium chloride hydrate?

Verified Answer :

Here are the missing information:
mass of empty crucible = 56.5622g

mass of crucible + hydrate before heating = 57.8310g

mass of crucible + hydrate after heating
(a) first reading = 57.6398g

(b) second reading = 57.6374g

(c) third reading = 57.6362g

Answers: 

1)
57.8310g - 56.5622g = 1.2688 g hydrate 

2)
57.6362g - 56.5622g = 1.07400 g anhydride 

3)
57.8310g - 57.6362g = 0.1948 g water 


4)
(0.1948 g water) / (1.2688 g hydrate) = 0.1535 = 15.35% water 


5)
15.35% water = 84.65% BaCl2 

(208.2330 g/mol BaCl2) / (0.8465) = 245.99 g/mol hydrate 

((245.99 g/mol) - (208.2330 g/mol BaCl2)) / (18.01532 g H2O/mol) = 2.096 

Round to the nearest whole number (2) to find the molar ratio of water to BaCl2:
BaCl2·2H2O