Chemical equation

Definition

A chemical equation is a symbolic representation of a chemical reaction, showing the reactants and products with their respective quantities. It must obey the law of conservation of mass, meaning the number of atoms for each element must be equal on both sides.

5 Must Know Facts For Your Next Test

1. Chemical equations use chemical formulas to represent reactants and products.
2. Balancing a chemical equation ensures that the same number of each type of atom appears on both sides.
3. Coefficients are used in front of compounds to balance the equation, not subscripts within formulas.
4. A balanced chemical equation allows for stoichiometric calculations to determine the amounts of reactants and products involved.
5. The phases of substances (solid, liquid, gas, aqueous) are often indicated in parentheses after each formula.

Review Questions

• What is the purpose of balancing a chemical equation?
• How do coefficients differ from subscripts in a chemical equation?
• Why is it important for a chemical equation to obey the law of conservation of mass?

Related terms

Reactant:

A substance that takes part in and undergoes change during a reaction.

Product:

A substance that is formed as the result of a chemical reaction.

Stoichiometry:

The calculation of reactants and products in chemical reactions based on the balanced equations.