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1 Mole is equivalent to 6.023 x 10²³ (Avogadro's number) units of any substance.

 

Chemical formula is the number of each type of atom in the smallest viable unit of the substance.
Empirical formula is the simplest possible ratio of elements in a substance.

By definition the molecular formula will be an integral number of empirical formulae (x1, x2 etc)

Examples:

Calculation of percentage composition

The simplest ratio of the number of moles of reactants and products in a chemical reaction. The balancing numbers are known as the coefficients of the reaction. Use of balancing number is essential to fulfill the law of conservation of matter. The overall set of balancing coefficients of a chemical reaction is known as the reaction stoichiometry

State symbols: (s)-Solid , (l)-liquid, (g)-gas, (aq)-aqueous solution...ie something dissolved in water. These should be included in all chemical reactions.

The ratio of two reacting masses will be always maintained for a specific chemical reaction. These mass ratios can be found from the stoichiometry (balancing numbers) of the equation and the molar masses of the reactants and products

Limiting reagent is a term used to describe the product which will completely react leaving other reactants unused.

The reactant left behind unused at the end of a reaction is said to be in excess

Solvent - the dissolving medium (usually water)

Solute - the substance that is dissolved.

Solution - the above components when mixed together intimately so that the solid phase becomes indistinguishable from the liquid phase.

Concentration - the amount of solute per amount of solvent (units mols per dm³ (litre) or grams per litre)

Concentration = ^{grams or moles}/_{volume (also called Molarity)}