Chemical word equations

 

What are chemical word equations?

A word equation is a way of writing a chemical reaction using the names of the substances that are involved. It shows what substances react together and what substances are formed as a result. Word equations are useful because they are simple and clear to understand and communicate, rather than writing a long description of the reaction.

 

Word equations also help us to record and share our work with others. For example, instead of writing this:

“When sodium and hydrochloric acid react, they produce sodium chloride and hydrogen.”

We can write a word equation like this:

sodium + hydrochloric acid → sodium chloride + hydrogen

 

What are the rules for writing word equations?

The rules for writing word equations are as follows:

 

• The names of the reactants are written first, separated by plus signs (+).
• An arrow (→) is used to show that a chemical reaction has occurred.
• The names of the products are written after the arrow, separated by plus signs (+).
• No words that describe the physical state or appearance of the substances, such as powder, solution or gas, are used in word equations.

 

How are chemical word equations different from chemical symbol equations?

Instead of using the names of the substances, chemical equations use the symbols and formulae of the elements and compounds that are involved in chemical reactions. For example, this is a chemical equation:

C + O2 → CO2

This equation uses the symbols of the elements carbon (C) and oxygen (O), which are found in the periodic table. It also uses the formula of the compound carbon dioxide (CO2), which shows how many atoms of each element are in one molecule.

A chemical word equation uses the names of the substances, but the order of the equation is similar to a chemical equation. For example, this is a chemical word equation for the same reaction:

carbon + oxygen → carbon dioxide

 

Summary:

 

• A chemical reaction can be described using the names of the substances that are involved in it. This is called a word equation.
• Word equations do not show any chemical symbols or formulae, only the names of the substances.
• In a word equation, the substances that react together are called reactants, and the substances that are formed are called products.
• A word equation has the format, reactants → products. A plus sign (+) is used to separate two or more reactants or products.