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?

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

level 4 to level 2 : ))

the answer your looking for is c).