Chem 1 Test 3 Flashcards

Solutions and Components

• A solution is a homogeneous mixture comprising a solvent and solute(s).
• The solvent is the medium that dissolves the solute, typically present in the greatest quantity and retains its physical state.
• Aqueous solutions specifically use water as the solvent.
• A solute is the substance that dissolves in a solvent to form a solution; it may alter its physical state.

Concentration and Preparation

• Molarity measures the concentration of a solution, defined as the amount of solute in moles divided by the volume of the solution in liters.
• A standard solution is one with a precisely known concentration.
• Solutions can be prepared either from a pure solute or through dilution of a concentration solution, often termed a "stock solution."

Water and Hydration

• Water has a molecular structure characterized by a bond angle of 105 degrees, making it polar with an unequal charge distribution.
• Hydration involves the attraction of water molecule's positive ends to anions and negative ends to cations when ionic compounds dissolve in water.

Electrolytes

• Solutes in water are categorized as electrolytes (conduct electricity) or nonelectrolytes (do not conduct electricity).
• Strong electrolytes are entirely ionized in solution, while weak electrolytes produce relatively few ions.
• Non-electrolytes do not dissociate into ions, maintaining their molecular integrity in solution.

Types of Reactions

• Solution reactions can include precipitation, acid-base, and oxidation-reduction reactions.
• Precipitation reactions create an insoluble solid called a precipitate by mixing solutions of two strong electrolytes, useful in chemical analysis.
• Gravimetric analysis quantifies substances by measuring the mass of the precipitate formed.

Acids and Bases

• An acid generates H+ ions in water and acts as a proton donor; a base produces OH- ions and functions as a proton acceptor.
• Properties of acids include a sour taste, ability to turn blue litmus red, electrical conductivity in aqueous form, and reactions with metals and carbonates.
• Properties of bases encompass a bitter taste, slippery feel, their ability to form insoluble metal compounds, turning red litmus blue, and electrical conductivity.

Stoichiometry and Indicators

• The stoichiometric point or equivalence point marks the complete reaction between an acid and a base.
• Indicators are substances that exhibit distinct color changes in acidic versus basic environments.