Hydrates Naming/Formula Writing, % Water, Solve for "X"

The chemical formula of sodium hydroxide pentahydrate is:

• NaO·5H2O

• NaOH·6H2O
• NaOH·5H2O
• NaOH·7H2O

The chemical formula of sodium carbonate monohydrate is:

• Na2CO4·H2O
• Na2CO3·2H2O
• NaCO3·H2O
• Na2CO3·H2O

• Copper (III) sulfate hexahydrate

• Copper (II) sulfate hexahydrate
• Copper (II) sulfate anhydrous
• Copper (II) sulfate pentahydrate

• Magnesium nitrate hydrate

• Magnesium nitrate one hydrate

• Magnesium nitrate monohydrate
• Magnesium nitrate dihydrate

A hydrate of magnesium carbonate weighs 4.35 grams. It is heated for 2 hours, and the resulting anhydrate weighs 3.33 grams. What was the % water in the hydrate?

A sodium carbonate dihydrate is heated until no water remains. 36.0 g of water were driven off and the final mass of sodium carbonate is 45.1g. Solve for % water.

A calcium chloride weighs 5.67 grams. After heating, the anhydrate weighed 3.56 grams. What is the chemical formula of the hydrate?

• CaCl₂·2H2O

• CaCl₂·4H2O

• CaCl₂·3H2O

• CaCl₂·H2O