Definition

1. Noun:
   • The quantitative relationship between reactants and products in a chemical reaction: Stoichiometry is the calculation of the relative quantities of substances involved in chemical reactions, based on the law of conservation of mass and the concept of moles.
   • The study of the proportions in which elements combine to form compounds: It involves determining the fixed ratios by mass or by number of atoms in which chemical elements combine.

Usage Examples

• Noun:
  • Balancing the chemical equation is the first step in solving the stoichiometry problem.
  • The stoichiometry of the reaction shows that two molecules of hydrogen react with one molecule of oxygen to form water.
  • Understanding stoichiometry is essential for predicting the amount of product formed in a reaction.

Advanced Usage

• "Reaction stoichiometry": Refers specifically to the quantitative relationships between substances as they participate in a particular chemical reaction.
  • The lab report requires a detailed analysis of the reaction stoichiometry.
• "Composition stoichiometry": Deals with the mass relationships of elements in compounds.
  • We used composition stoichiometry to determine the empirical formula of the unknown substance.

Variants and Related Words

• Stoichiometric (adj): Of or relating to stoichiometry; present in the exact ratio required for a complete reaction.
  • A stoichiometric mixture of fuel and air provides optimal combustion.
• Nonstoichiometric (adj): Not having the exact proportions indicated by a simple chemical formula; often used for certain solid compounds or crystals.
  • Some transition metal oxides are nonstoichiometric compounds.

Synonyms

• Chemical proportion: The ratio of combining weights or amounts in a chemical process.
• Quantitative relationship: A connection expressed in measurable amounts, particularly in chemistry.

Related Phrases

• "Stoichiometric coefficient": The number written in front of a substance in a balanced chemical equation.
  • In the equation 2H₂ + O₂ → 2H₂O, the stoichiometric coefficient for hydrogen is 2.
• "Stoichiometric calculation": A mathematical problem involving the amounts of reactants and products.
  • The final exam will include several stoichiometric calculations.

Noun

1. (chemistry) the relation between the quantities of substances that take part in a reaction or form a compound (typically a ratio of whole integers)