Stoichiometry, Formulas, and Reaction Yields

Vocabulary practice flashcards covering empirical and molecular formulas, combustion analysis, chemical equations, stoichiometry, limiting reactants, and reaction yields based on Chapter 3 lecture notes.

Empirical Formula

The simplest formula for a compound that agrees with elemental analysis, showing the lowest whole-number ratio of moles and relative number of atoms of each element present.

Molecular Formula

A formula that shows the actual number of atoms of each element in a molecule of a compound, represented as a whole-number multiple of the empirical formula.

Structural Formula

A chemical formula that depicts the relative placement and connections of atoms within a molecule.

Formaldehyde

An organic compound with empirical and molecular formula $CH_2O$, molar mass $30.026\,g\,mol^{-1}$, and whole-number multiple $1$, used as a disinfectant and biological preservative.

Acetic Acid

A compound with molecular formula $C_2H_4O_2$, molar mass $60.052\,g\,mol^{-1}$, and empirical formula multiplier $2$, used in acetate polymers and vinegar ($5\%$ solution).

Glucose

A carbohydrate with molecular formula $C_6H_{12}O_6$, molar mass $180.156\,g\,mol^{-1}$, and whole-number multiple $6$, serving as a major nutrient for energy in cells.

Fructose

A monosaccharide with molecular formula $C_6H_{12}O_6$, molar mass $180.156\,g\,mol^{-1}$, and whole-number multiple $6$, used as a sweetener for foods and beverages.

Combustion Analysis

An analytical laboratory method used to measure the amounts of carbon and hydrogen in a combustible organic compound by absorbing and weighing produced $CO_2$ and $H_2O$.

Combustion Apparatus

An experimental apparatus comprising an $O_2$ supply stream, a sample combustion furnace, an $H_2O$ absorber, and a $CO_2$ absorber used to analyze combustible organic compounds.

Chemical Equation

An expression using chemical formulas to show the identities and relative quantities of substances involved in a chemical or physical change.

Stoichiometrically Equivalent Molar Ratios

Conversion factors derived from the coefficients of a balanced chemical equation that express quantitative molar relationships between reactants and products.

Limiting Reactant

The reactant in a chemical reaction that is completely consumed first, 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 remaining after the reaction stops.

Theoretical Yield

The maximum calculated mass or amount of product obtained from the stoichiometric molar ratios of a balanced chemical equation.

Actual Yield

The amount of product that is experimentally obtained from a chemical reaction, which is typically less than the theoretical yield.

Percent Yield

The percentage ratio of actual yield to theoretical yield, given by the expression: $\text{\% yield} = \frac{\text{actual yield}}{\text{theoretical yield}} \times 100$.

Side Reaction

A secondary reaction competing with the main reaction path, diverting reactants into an unwanted side product and lowering the yield of the main product.