A material that settles out of a reaction is termed a

• A. product
• B. solid
• C. precipitate
• D. reactant

Answer: (C)

When a solid forms and settles out of a reaction mixture, that solid is called a precipitate. This term specifically describes an insoluble substance that comes out of solution during a reaction, leaving the liquid phase behind. A precipitate indicates that the product is not just formed, but also that its solubility is exceeded under the reaction conditions, causing it to separate as a solid. In contrast, a product is any substance produced in the reaction, which can be solid, liquid, or gas and may remain dissolved. A solid is simply a physical state and doesn’t by itself describe how it appears in the reaction. A reactant is a starting material consumed during the reaction. So the best label for a solid that forms and settles from solution is precipitate.