Basics
Define a chemical equation
A representation of a chemical reaction using symbols and formulas.
H₂ + O₂ → H₂O
2H₂ + O₂ → 2H₂O
Why balance chemical equations?
To follow the Law of Conservation of Mass and ensure accurate chemical reactions.
H₂O₂ → H₂O + O₂
2H₂O₂ → 2H₂O + O₂
What type of reaction follows the general formula A + B → AB, where two or more reactants combine to form a single product?
Synthesis
Identify reactants and products
Reactants are substances that start the reaction; products are substances formed.
Fe + O₂ → Fe₂O₃
4Fe + 3O₂ → 2Fe₂O₃
Example of an unbalanced reaction in agriculture.
Any of our posters!
SO₂ + O₂ → SO₃
2SO₂ + O₂ → 2SO₃
What type of reaction follows the formula AB → A + B, where a compound breaks down into simpler substances?
Decomposition reaction
What does the arrow (→) mean?
It shows the direction of the reaction, meaning "yields" or "produces."
CH₄ + O₂ → CO₂ + H₂O
CH₄ + 2O₂ → CO₂ + 2H₂O
How do fertilizers involve chemical reactions?
Fertilizers release nutrients like nitrogen through reactions with water and soil.
C₂H₆ + O₂ → CO₂ + H₂O
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
In the reaction A + BC → AC + B, one element replaces another in a compound. What is this type of reaction called?
Single Replacement reaction
What law requires balancing?
KClO₃ → KCl + O₂
2KClO₃ → 2KCl + 3O₂
How does combustion relate to chemical equations?
It involves hydrocarbon fuels reacting with oxygen to produce CO₂ and H₂O, like C₃H₈ + O₂ → CO₂ + H₂O
Fe + Cl₂ → FeCl₃
2Fe + 3Cl₂ → 2FeCl₃
What type of reaction follows the general formula AB + CD → AD + CB, where the ions of two compounds switch places?
Double Replacement reaction
What are coefficients used for?
To balance chemical equations and indicate the number of molecules or atoms involved.
Zn + H₂SO₄ → ZnSO₄ + H₂
Zn + H₂SO₄ → ZnSO₄ + H₂
A chemical equation in agriculture!
C₄H₁₀ + O₂ → CO₂ + H₂O
2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O
A hydrocarbon reacts with oxygen to produce carbon dioxide and water. What is the general formula for this reaction?
CxHy + O₂ → CO₂ + H₂O