Which of the following best describes grain alcohol (ethanol) in terms of classification of matter?

• A. It is an element.
• B. It is a heterogeneous mixture.
• C. It is a pure substance.
• D. It is a homogeneous mixture.

Answer: (C)

Verified step by step guidance

1. Recall the basic classifications of matter: elements, compounds, homogeneous mixtures, and heterogeneous mixtures.
2. Understand that an element consists of only one type of atom, while a compound consists of two or more elements chemically combined in a fixed ratio.
3. Recognize that mixtures (both homogeneous and heterogeneous) contain two or more substances physically combined, not chemically bonded.
4. Identify ethanol (grain alcohol) as a compound because it is chemically composed of carbon, hydrogen, and oxygen atoms in a fixed ratio (C2H5OH).
5. Since ethanol is a single chemical substance with uniform composition throughout, it is classified as a pure substance, not a mixture or element.