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?

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