Stoichiometry of Formulas and Equations

Vocabulary flashcards covering core stoichiometry concepts including molar mass, formulas, reaction balancing, limiting reactants, and yields.

Mole (mol)

The amount of a substance that contains the same number of entities (atoms, ions, molecules, formula units, or electrons) as there are atoms in exactly $12\,g$ of carbon-12.

Avogadro's Number

The number of chemical entities contained in one mole of a substance, equal to $6.022 \times 10^{23}$.

Molar Mass ($M$)

The mass in grams of one mole of a substance's entities (atoms, molecules, or formula units), expressed in $g\,mol^{-1}$.

Empirical Formula

The simplest chemical formula for a compound that shows the lowest whole-number molar ratio of atoms of each element present.

Molecular Formula

A chemical formula that gives the actual number of atoms of each element in a molecule of a compound.

Structural Formula

A chemical formula that shows the relative placement and connections between atoms within a molecule.

Combustion Analysis

An analytical method used to determine the amounts of carbon and hydrogen in a combustible organic compound by burning it in an atmosphere of $O_2$ and absorbing the generated $H_2O$ and $CO_2$.

Isomers

Different chemical compounds that share the exact same molecular formula but possess different structural arrangements and properties.

Chemical Equation

A written representation that uses formulas and coefficients to express the identities and relative quantities of substances involved in a physical or chemical change.

Limiting Reactant

The reactant that is completely consumed in a chemical reaction, thereby limiting the maximum amount of product that can form.

Excess Reactant

The reactant in a chemical reaction that is not completely consumed, leaving an unreacted portion when the reaction stops.

Theoretical Yield

The maximum quantity of product calculated using the stoichiometrically equivalent molar ratios from a balanced chemical equation.

Actual Yield

The mass or amount of product actually obtained and isolated experimentally from a chemical reaction.

Percent Yield

The proportion of the actual yield relative to the theoretical yield, calculated as $\%\text{ yield} = \frac{\text{actual yield}}{\text{theoretical yield}} \times 100\%$.