General Chemistry: Moles, Stoichiometry, and Quantitative Analysis

Vocabulary practice flashcards covering fundamental chemistry principles, including mole calculations, empirical/molecular formulas, stoichiometry, limiting reagents, percent yields, and quantitative analytical techniques.

The Mole

The amount of a substance containing a number of atoms equal to the number of carbon atoms in exactly $12\,\text{g}$ of pure $^{12}\text{C}$, corresponding to $6.022 \times 10^{23}$ units.

Avogadro's Number

The fixed number of fundamental units in one mole of any substance, defined as $6.022 \times 10^{23}$.

Molar Mass

The mass in grams of one mole of a given chemical substance, typically expressed in units of $\text{g/mol}$.

Mass Percent

The percentage composition of an element in a compound by mass, calculated as $\text{mass \% } = \frac{\text{mass of element in compound}}{\text{mass of compound}} \times 100\%$.

Empirical Formula

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

Molecular Formula

The actual chemical formula of a compound specifying the exact number of atoms of each element in a molecule, related to the empirical formula by an integer multiplier $n$.

Combustion Analysis

An analytical method in which a sample containing carbon and hydrogen is rapidly reacted with excess oxygen to form carbon dioxide ($\text{CO}_2$) and water ($\text{H}_2\text{O}$) to determine its empirical formula.

Chemical Equation

A symbolic representation of a chemical reaction showing reactants on the left side converting into products on the right side.

Stoichiometry

The quantitative study of reactants and products in a balanced chemical equation using mole ratios to calculate amounts consumed or produced.

Limiting Reagent

The reactant that is completely consumed first during a chemical reaction, thereby limiting the total quantity of product that can be formed.

Theoretical Yield

The maximum amount of product that would be obtained from a chemical reaction if the limiting reactant were completely converted according to stoichiometry.

Actual Yield

The quantity of product that is actually measured and collected from a chemical reaction performed in a laboratory or industrial setting.

Percent Yield

An indicator of reaction efficiency calculated as $\text{percent yield} = \frac{\text{Actual yield}}{\text{Theoretical yield}} \times 100\%$.

Gravimetric Analysis

A quantitative analytical method in which the amount of a constituent in a sample is determined by isolated precipitation, drying, and precise mass measurement.

Volumetric Analysis

A quantitative analytical technique, such as titration, where the concentration of an analyte is determined by measuring the volume of a standard solution required to complete the reaction.

Molarity

A measure of concentration equal to the number of moles of solute per liter of solution ($\text{Molarity (M)} = \frac{\text{moles of solute}}{\text{liters of solution}}$).