A number placed in front of a formula to balance a chemical reaction.
Decomposition
A redox reaction in which a compound breaks up to form two elements.
Double replacement
A solution reaction in which the positive ion of one compound combines with the negative ion of the other compound to form a precipitate, and the other ions remain dissolved in solution.
Law of conservation of charge
Charge cannot be created or destroyed by physical or chemical change.This is the basis for writing chemical formulas and half-reactions, and balancing redox ionic reactions.
Law of conservation of energy
Energy cannot be created or destroyed by physical or chemical change. This is the basis for calculating the heat of reaction.
Law of conservation of mass
Matter cannot be created or destroyed by physical or chemical change. This is the basis for balancing chemical reactions.
Mole ratio
The whole-number ratio between components of a balanced chemical reaction.
Oxidation
The loss of electron(s), causing the oxidation number of a species to become more positive.
Precipitate
An insoluble solid that is formed either in a double-replacement reaction or as excess solute added to a saturated solution.
Product
The substances that are formed by a chemical reaction, designated as the right side of a chemical equation.
Reactant
The substances that are reacted together, designated as the left side of a chemical equation. Reaction A chemical change where reactants are turned into products.
Redox reaction
A reaction in which one element is oxidized and another element is reduced.
Reduction
The gain of electron(s), causing the oxidation number of a species to become more negative.