Chemical Equations

Study Notes

Chemical Equation

A chemical equation is a symbolic representation of a chemical reaction, using chemical formulas and symbols to illustrate the reactants, products, and direction of the reaction.

Components of a Chemical Equation

Reactants: substances that undergo a chemical change, written on the left side of the equation
Products: substances formed as a result of the chemical change, written on the right side of the equation
Arrow: indicates the direction of the reaction, pointing from reactants to products
Coefficients: numbers in front of formulas to indicate the mole ratio of reactants and products
State symbols: indicate the physical state of each substance (e.g., solid (s), liquid (l), gas (g), aqueous (aq))

Types of Chemical Reactions

Synthesis reaction: two or more substances combine to form a new compound
Decomposition reaction: a single substance breaks down into two or more simpler substances
Replacement reaction: one element replaces another element in a compound
- Single displacement reaction: one element replaces another element in a compound
- Double displacement reaction: two compounds exchange partners, forming two new compounds
Combustion reaction: a substance reacts with oxygen to produce heat and light

Balancing Chemical Equations

Law of Conservation of Mass: matter cannot be created or destroyed in a chemical reaction, only transformed
Balancing coefficients: adjust coefficients to ensure that the number of atoms of each element is equal on both sides of the equation
Step-by-step process: balance elements one at a time, starting with the most abundant element and working down to the least abundant

Reaction Stoichiometry

Mole ratio: the ratio of the number of moles of reactants to the number of moles of products
Limiting reactant: the reactant that is completely consumed during the reaction, determining the maximum amount of product formed
Excess reactant: the reactant that is not completely consumed during the reaction, remaining in excess after the reaction is complete

Chemical Equation

A symbolic representation of a chemical reaction, using chemical formulas and symbols to illustrate reactants, products, and direction of the reaction.

Components of a Chemical Equation

Reactants: substances that undergo a chemical change, written on the left side of the equation.
Products: substances formed as a result of the chemical change, written on the right side of the equation.
Arrow: indicates the direction of the reaction, pointing from reactants to products.
Coefficients: numbers in front of formulas to indicate the mole ratio of reactants and products.
State symbols: indicate the physical state of each substance (e.g., solid (s), liquid (l), gas (g), aqueous (aq)).

Types of Chemical Reactions

Synthesis reaction: two or more substances combine to form a new compound.
Decomposition reaction: a single substance breaks down into two or more simpler substances.
Replacement reaction: one element replaces another element in a compound.
Single displacement reaction: one element replaces another element in a compound.
Double displacement reaction: two compounds exchange partners, forming two new compounds.
Combustion reaction: a substance reacts with oxygen to produce heat and light.

Balancing Chemical Equations

Law of Conservation of Mass: matter cannot be created or destroyed in a chemical reaction, only transformed.
Balancing coefficients: adjust coefficients to ensure that the number of atoms of each element is equal on both sides of the equation.
Step-by-step process: balance elements one at a time, starting with the most abundant element and working down to the least abundant.

Reaction Stoichiometry

Mole ratio: the ratio of the number of moles of reactants to the number of moles of products.
Limiting reactant: the reactant that is completely consumed during the reaction, determining the maximum amount of product formed.
Excess reactant: the reactant that is not completely consumed during the reaction, remaining in excess after the reaction is complete.