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Chemical Equations
CHEMICAL EQUATIONS are used to show what happens during a chemical reaction. The LEFT hand side represents the REACTANTS and the RIGHT hand side represents the PRODUCTS.
- A WORD EQUATION expresses the reactants and products of a reaction in WORDS.
- A SYMBOL EQUATION is more CONCISE, using chemical symbols and FORMULAS to represent the reactants and products. For example, methane burning in oxygen can be written as:
However the symbol equation is NOT correct as it needs to be BALANCED.
Balancing Chemical Equations
- Symbol equations must be BALANCED, meaning they have the same number of each type of atom on both sides of the equation.
- To balance an equation, COEFFICIENTS (numbers in front of the formulas) are adjusted so that the number of ATOMS for each element is equal on both sides.
- The CONSERVATION OF MASS tells us that no atoms are LOST or GAINED in a chemical reaction, they are just REARRANGED.
- This means the equation needs to be BALANCED.
- To balance an equation you ADJUST the COEFFICIENTS until there are the SAME number of ATOMS of the SAME ELEMENT on each side.
Steps to Balance Equations
- Identify the number of atoms of EACH ELEMENT on either side of the equation.
- ADJUST the coefficients to balance that element, which may cause another element to become unbalanced.
- Repeat the process, adjusting coefficients as necessary until the equation is BALANCED.
Consider the reaction with methane and oxygen:
The Carbons are both balanced but the Hydrogens and the Oxygens are not.
You can put a 2 in front of WATER to make the reaction have 4 HYDROGENS on BOTH SIDES.
Now the Carbons and Hydrogens are both BALANCED but the Oxygens are NOT.
You can put a 2 in front of the OXYGEN to balance it.
Now the equation is BALANCED.
Chemical Equations
CHEMICAL EQUATIONS are used to show what happens during a chemical reaction. The LEFT hand side represents the REACTANTS and the RIGHT hand side represents the PRODUCTS.
- A WORD EQUATION expresses the reactants and products of a reaction in WORDS.
- A SYMBOL EQUATION is more CONCISE, using chemical symbols and FORMULAS to represent the reactants and products. For example, methane burning in oxygen can be written as:
However the symbol equation is NOT correct as it needs to be BALANCED.
Balancing Chemical Equations
- Symbol equations must be BALANCED, meaning they have the same number of each type of atom on both sides of the equation.
- To balance an equation, COEFFICIENTS (numbers in front of the formulas) are adjusted so that the number of ATOMS for each element is equal on both sides.
- The CONSERVATION OF MASS tells us that no atoms are LOST or GAINED in a chemical reaction, they are just REARRANGED.
- This means the equation needs to be BALANCED.
- To balance an equation you ADJUST the COEFFICIENTS until there are the SAME number of ATOMS of the SAME ELEMENT on each side.
Steps to Balance Equations
- Identify the number of atoms of EACH ELEMENT on either side of the equation.
- ADJUST the coefficients to balance that element, which may cause another element to become unbalanced.
- Repeat the process, adjusting coefficients as necessary until the equation is BALANCED.
Consider the reaction with methane and oxygen:
The Carbons are both balanced but the Hydrogens and the Oxygens are not.
You can put a 2 in front of WATER to make the reaction have 4 HYDROGENS on BOTH SIDES.
Now the Carbons and Hydrogens are both BALANCED but the Oxygens are NOT.
You can put a 2 in front of the OXYGEN to balance it.
Now the equation is BALANCED.
