Introduction to Chemistry, Matter, The Elements
1.2 Definitions of Matter I (Copper vs Copper sulfate)
Subjects: Introduction to chemistry, definitions of matter
Description: This demo illustrates two concepts: the difference between an element and a chemical compound as well as the difference between heterogeneous and homogeneous mixtures (solutions).
Materials:
- Copper metal
- Copper Sulfate - CuSO4
- 400 ml beaker
- Water
- Stir plate*
- Stir bar
- Spatula
*Shared item. Located in the top drawer opposite the chemical storage cabinets or on the shelf above the center bench.
Procedure:
- Prior to the demo, use the copper metal and CuSO4 to illustrate the concept of an element versus a chemical compound, both of which are pure substances.
- Place a beaker filled with water on a stir plate with a stir bar.
- Use a spatula to scoop in chunks of CuSO4.
- The copper sulfate will dissolve to produce a blue homogeneous solution.
Discussion: This demo illustrates the following concepts:
- An element is a substance composed of one type of atom.
- A chemical compound is a pure substance composed of two or more different elements held together by chemical bonds.
- Homogeneous means a mixture that consists of two or more substances in the same phase (ex: solution).
- Heterogeneous means a mixture in which the uneven texture of a material can be detected.
Disposal: Dispose of copper sulfate solution in appropriate aqueous waste container.
References:
1. J. Kotz, P. Treichel, J. Townsend; Chemistry and Chemical Reactivity, 7th Ed; Thomson Brooks/Cole; 2009
