General Chemistry for Engineers — Chapter 3: Molecules, Moles, and Chemical Equations (VOCABULARY Flashcards)

Vocabulary flashcards covering key terms from Chapter 3 on molecules, moles, and chemical equations. Definitions are concise and aligned with the notes.

Mole

A counting unit for chemical species; the amount of substance containing 6.022 × 10^23 particles.

Avogadro's number

6.022 × 10^23 particles per mole; the number of particles in one mole of any substance.

Molar Mass

Mass of one mole of a substance; sum of atomic masses in its formula.

Molarity (M)

Moles of solute per liter of solution.

Dilution

Process of adding solvent to a solution to lower concentration; moles of solute remain the same.

Solute

Substance dissolved in solvent.

Solvent

Component of a solution present in the greatest amount.

Solution

A homogeneous mixture of solute and solvent; often aqueous.

Solubility

Ability of a solute to dissolve in a solvent under specified conditions.

Solubility guidelines

Rules predicting solubility of salts in water (25°C) based on ion types with soluble, moderately soluble, and insoluble categories and exceptions.

Electrolyte

Substance that conducts electricity in solution due to ions; includes strong and weak electrolytes.

Nonelectrolyte

Substance that does not form ions in solution and does not conduct electricity.

Strong electrolyte

Dissociates completely into ions in solution.

Weak electrolyte

Dissociates only partially into ions in solution.

Strong acid

Acid that fully dissociates in water (e.g., HCl, HNO3, H2SO4, HClO4, HI, HBr).

Weak acid

Acid that partially dissociates in water (e.g., acetic acid; examples listed in notes include HF, H3PO4 to some extent).

Strong base

Base that completely dissociates in water (e.g., NaOH, KOH, Ba(OH)2, Ca(OH)2, LiOH, Sr(OH)2).

Weak base

Base that partially dissociates in water (e.g., NH3, CH3NH2).

Acid-base neutralization

Reaction between an acid and a base producing water and a salt; solutions often become neutral.

Net ionic equation

Ionic equation showing only species that undergo a change; spectator ions are omitted.

Spectator ions

Ions present in solution but not involved in the reaction.

Total ionic equation

Equation showing all ions present for strong electrolytes in solution.

Molecular equation

Equation showing the complete formulas of reactants and products, not ions.

Precipitation reaction

Aqueous reaction that forms a solid precipitate.

Dissociation

Process by which an ionic compound separates into ions in water.

Aqueous reaction

Reaction occurring in water; may involve molecular or ionic species.

Phase notation

Phase labels after formulas: s = solid, l = liquid, g = gas, aq = aqueous.

Stoichiometric coefficient

Coefficient multiplying the number of atoms or molecules in a formula unit in a balanced equation.

Law of conservation of mass

Matter is neither created nor destroyed in a chemical reaction; atoms are rearranged.

Balanced chemical equation

An equation with equal numbers of each type of atom on both sides.

Empirical formula

The simplest whole-number ratio of elements in a compound.

Molecular formula

The actual number of each type of atom in a molecule; a whole-number multiple of the empirical formula.

Elemental analysis

Technique to measure mass percentages of elements to determine empirical formula.

Percent composition

The mass percentage of each element in a compound.

Empirical formula from percent composition

Process of converting mass percentages to moles, then to the smallest whole-number ratio.

Molarity from dilution (M1V1 = M2V2)

Relation used to calculate concentrations or volumes when diluting solutions.

Carbon sequestration

Process of removing carbon from the atmosphere or from gases entering it; carbon flow among reservoirs.

Biomass

Biological material derived from plants used as an energy source.

Photosynthesis

Process by which plants convert sunlight into sugars, forming biomass.

Biofuel

Fuels derived from biomass.