Equation Basics

• In Chemistry, equations are used to demonstrate the reaction between reactants and products.
• In this document, you will find the information necessary in order to form the foundation of the knowledge of equations.

Structure

• The structure of equations can be followed through this formula.

Equation Structure Formula

• In each side, reactants/products can have coefficients that determine the amount of molecules it contains. For example, (electrolysis of water) has two water molecules as reactants, while it has two diatomic hydrogen molecules and one diatomic oxygen molecule as its products.

Law of Conservation of Mass

Related Concepts

• This is related to Balancing Chemical Equations (Balancing Equations).

• The Law of Conservation of Mass is defined as atoms being unable to be created nor destroyed, only rearranged.
• The total mass of products is always equal to the total mass of reactants.
• In order to balance equations, the same number of each type of atom must be on both sides to ensure the mass is equal.

Balancing Equations

• Refer to Balancing Chemical Equations.
• In simple terms, balancing is all about ratios and equality.

State Symbols

• State symbols must always be used in order to determine a reactant or product’s chemical species.
• This can be used as a subscript below a reactant or product. Here are some state symbols.
  • Solid (s)
  • Liquid (l)
  • Gas (g)
  • Aqueous (aq)
    • A solution formed when something dissolved with water, typically used with ionic substances that dissolve in water.
    • For example, .
• You can guess or know the state of a reactant or product’s chemical species through the following methods.
  • It may be a common example at room temperature (e.g. hydrogen and oxygen are gases at room temperature).
  • It may be a specific reaction that has been studied in the past, which allows you to know the states of said reactants or products.
  • It will be told in the wording of the question.