Stoichiometry

Introduction to Stoichiometry

• Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in a chemical reaction.
• It allows chemists to predict how much of a reactant is needed to form a certain amount of product, or conversely, how much product is formed from a certain amount of reactant.

Concept of Mole

• A mole is a standard unit in chemistry, used to measure the amount of a substance. It is based on the concept that 12 grams of carbon-12 consists of exactly one mole of carbon-12 atoms (approximately 6.02 × 10^23 atoms).
• The number of particles (atoms, molecules, or ions) in a mole is known as Avogadro’s number (6.02 × 10^23).

Molar Mass

• The molar mass of a substance is the mass of one mole of that substance, measured in grams per mole (g/mol).
• The molar mass of an element is numerically equal to the atomic mass of the element.
• For compounds, the molar mass is the sum of the molar masses of the constituent atoms.

Balanced Chemical Equations

• A balanced chemical equation represents a chemical reaction and is fundamental in stoichiometry.
• It indicates the proportion of moles of each reactant necessary to form a certain number of moles of product.

Mole Ratio

• The mole ratio is the ratio of moles of one substance to another in a chemical reaction, based on the balanced chemical equation.

Stoichiometric Calculations

• There are numerous stoichiometric calculations that we can perform, such as:
  • Determining the amount of product formed from a given amount of reactant.
  • Determining the amount of reactant needed to form a given amount of product.
  • Determining the percent yield of a reaction.
  • Calculating the limiting reactant in a reaction.

Remember that stoichiometry relies on accurate, balanced chemical equations. Always double-check your equation before beginning calculations.