Identify the following as a homogeneous mixture, a heterogeneous mixture, an element, or a chemical compound. a. air b. pancake batter c. brass (an alloy of copper and zinc) d. table salt (sodium chloride)
The Correct Answer and Explanation is:
Here are the identifications:
a. Air – Homogeneous mixture
b. Pancake batter – Heterogeneous mixture
c. Brass (an alloy of copper and zinc) – Homogeneous mixture
d. Table salt (sodium chloride) – Chemical compound
Explanation
Matter can be classified into pure substances (elements and compounds) and mixtures (homogeneous and heterogeneous).
Air is a homogeneous mixture because it consists of gases like nitrogen, oxygen, carbon dioxide, and others that are evenly mixed at the molecular level. Even though it’s made up of different substances, it has uniform composition and properties throughout, and no individual components are visible.
Pancake batter, on the other hand, is a heterogeneous mixture. While it may seem uniform when mixed, it often contains clumps of flour, tiny air bubbles, or other ingredients that are not evenly distributed. The non-uniformity and presence of visible differences in texture or composition qualify it as a heterogeneous mixture.
Brass, an alloy of copper and zinc, is a homogeneous mixture. Though it consists of more than one metal, the metals are mixed so thoroughly at the atomic level that they form a uniform composition. You cannot see the individual metals with the naked eye, and brass appears as one consistent phase.
Table salt, chemically known as sodium chloride (NaCl), is a chemical compound. It forms when sodium (a metal) and chlorine (a non-metal) react in a fixed 1:1 ratio to produce a substance with new properties. Unlike mixtures, compounds have components that are chemically bonded, and the properties of the compound differ from those of the individual elements. Sodium is highly reactive, and chlorine is toxic, yet NaCl is safe and edible—this is characteristic of chemical compounds.
In summary, the classification of matter depends on its composition and uniformity. Understanding these categories helps in identifying materials and predicting their behavior in physical and chemical processes.
