# stoichiometry

(noun)

## Definition of stoichiometry

the study and calculation of quantitative (measurable) relationships of the reactants and products in chemical reactions (chemical equations)

Source: Wiktionary - CC BY-SA 3.0

## Examples of stoichiometry in the following topics:

• ### Solution Stoichiometry

• In previous atoms, stoichiometry has been discussed in a general sense.
• A specific area of stoichiometry pertains to its application to solutions.ConcentrationA solution consists of two components: solute (the dissolved material) and solvent (the liquid in which the solute is dissolved).
• The mole fraction (X) of a given solute in a solution is the ratio of the moles of that soute (ms) to the sum of moles of all species in the solution (mt):$X=\frac {m_s}{m_t}$Reaction Stoichiometry In SolutionsReaction stoichiometry in solutions is analogous to reaction stoichiometry in any other state.
• Stoichiometry is a tool used by chemists to calculate relative amounts of reactants and products in a reaction.
• ### Reaction Stoichiometry

• Stoichiometry is a branch of chemistry that deals with the relative quantities of reactants and products in chemical reactions.
• Reaction stoichiometry describes the quantitative relationships among substances as they participate in chemical reactions.
• In the example above, reaction stoichiometry describes the 1:3:2 ratio of molecules of nitrogen, hydrogen, and ammonia.
• A reaction may consume more than one molecule; the stoichiometric number counts this number, defined as positive for products (added) and negative for reactants (removed).Balancing EquationsStoichiometry is often used to balance chemical equations (reaction stoichiometry).
• The reactions may differ in their stoichiometry.
• Reaction stoichiometry describes the relationships between the components of a given reaction.
• ### Gas Stoichiometry

• Stoichiometry is the quantitative study of the relative amounts of reactants and products in chemical reactions.
• Gas stoichiometry is the special case involving chemical reactions that produce gases.
• Stoichiometry is based on the law of conservation of mass, meaning that the mass of the reactants must be equal to the mass of the products.
• Gas stoichiometry applies when the gases produced are assumed to be ideal, and the temperature, pressure, and volume of the gases are all known.
• However, a chemical equation's stoichiometry is given in terms of moles, not grams.
• Gas stoichiometry describes the relative amounts of reactants and products in reactions used to calculate their masses and volumes.
• ### Amount of Reactants and Products

• Stoichiometry is the field of chemistry that is concerned with the relative quantities of reactants and products in chemical reactions.
• In addition, stoichiometry can be used to find quantities such as the amount of products that can be produced with a given amount of reactants and percent yield.
• Reaction stoichiometry describes the quantitative relationship among substances as they participate in various chemical reactions.
• ### The Law of Multiple Proportions

• The Law of Multiple Proportions is a rule of stoichiometry.
• ### Limiting Reagents

• From stoichiometry, the exact amount of reactant needed to react with another element can be calculated.
• Then, use stoichiometry to calculate the mass of the product that could be produced for each individual reactant.
• ### Carbides

• When the metal atoms are cubic-close-packed (ccp), then filling all of the octahedral interstices with carbon achieves 1:1 stoichiometry with the rock-salt structure.
• When the metal atoms are hexagonal-close-packed, (hcp), since the octahedral interstices lie directly opposite each other on either side of the layer of metal atoms, filling only one of these with carbon achieves 2:1 stoichiometry.
• ### Molar Mass of Gas

•  This knowledge can help us to determine the stoichiometry needed to balance chemical reactions.
• ### Ionic Crystals

• You might think that this corresponds to Na6Cl6, but note that the central sodium ion shown in the diagram can claim only a one-sixth share of each of its chloride ion neighbors, so the formula NaCl is not just the simplest formula, but correctly reflects the 1:1 stoichiometry of the compound.
• In ionic solids of even the simplest 1:1 stoichiometry, the positive and negative ions usually differ so much in size that packing is often much less efficient.
• ### Using Molarity in Calculations of Solutions

• The proper procedure in making a 1.0M solution would be to dissolve the salt in less than a liter of water, and then slowly add more water while mixing, until the total volume reached 1.00 liter.The advantage of expressing concentrations in terms of molarity is that these solutions can now be used in chemical reactions of known stoichiometry.