Single replacement reactions happen when one element takes the place of another in a compound.

You can think of this type of reaction like a simple formula:

A + BC → AC + B

In this formula, "A" is usually a more active element that pushes "B" out of the compound "BC."

Example of a Single Replacement Reaction:

Let’s look at a common example:

• Zinc and Hydrochloric Acid Reaction:

When zinc (Zn) mixes with hydrochloric acid (HCl), it reacts like this:

Zn + 2 HCl → ZnCl₂ + H₂

In this reaction, zinc replaces hydrogen in the acid. This creates zinc chloride (ZnCl₂) and hydrogen gas (H₂).

Signs of Single Replacement:

Here are some clues that a single replacement reaction has happened:

• A gas is formed (like H₂ in our example)
• A solid is created (called a precipitate)
• The solution changes color

These types of reactions help us learn about how elements react with each other. They are important for fields like metallurgy (working with metals) and electrochemistry (the chemistry of electricity)!