Real-Life Chemical Reactions and Product Purity

• A pure substance contains only one type of particle and has sharp fixed melting and boiling points.
• A mixture contains two or more substances that are physically combined but not chemically bonded.
• A by-product is an unwanted substance produced during a reaction.
• Yield refers to how much product you actually collected compared to what you expected.

Example

When carbon burns in oxygen, you expect it to produce carbon dioxide. However, because oxygen is limited, you also get carbon monoxide as a by-product.

How to Detect Impurities

Impurities affect the physical properties of a substance.

• A pure substance affects the physical properties of a substance.
• A pure substance melts at one exact temperature.