A chemical substance that has had its water of crystallization removed is described as what?

• A. Solvated
• B. Hydration
• C. Anhydrous
• D. Miscible

Answer: (C)

When a crystalline substance contains water as part of its structure, it is called a hydrate with water of crystallization. If that water is removed, the remaining solid has no water and is described as anhydrous. This is the term that specifically means “without water.” The process of removing the water is dehydration, yielding the anhydrous form. The other terms don’t fit here: solvated implies water molecules are part of the formula as solvent within the solid, hydration refers to the presence of water in the compound rather than its absence after removal, and miscible describes liquids that mix together rather than a solid’s water content.