A 92.8 gram sample of Ba (OH) 2•4H2O (barium hydroxide tetrahydrate) is heated until water is released. How many grams of water were released?

From the periodic table:

molar mass of barium = 137.2 grams

molar mass of oxygen = 16 grams

molar mass of hydrogen = 1 gram

molar mass of Ba (OH) 2 = 137.2 + 2 (16) + 2 (1) = 171.2 grams

molar mass of 4H2O = 4 [2 (1) + 16] = 72 grams

molar mass of Ba (OH) 2.4H2O = 171.2 + 72 = 243.2 grams

Therefore, each 243.2 grams of barium hydroxide tetrahydrate contains 72 grams of water, thus, 92.8 grams will contain:

mass of water in 92.8 grams = (92.8 x 72) / 243.2 = 27.474 grams

Based on this, when a 92.8 gram sample of Ba (OH) 2•4H2O (barium hydroxide tetrahydrate) is heated until water is released, 27.474 grams of water will be released.