Acids and Bases Overview

Acids and bases are fundamental chemical substances with distinctive properties and applications. They play crucial roles in various chemical reactions and processes.

The Arrhenius theory defines acids as substances that produce hydrogen ions (H+) when dissolved in water, while bases produce hydroxide ions (OH-) in water.

Hydrochloric acid (HCl), a strong acid, releases hydrogen ions (H+) when dissolved in water, making the solution acidic.

Sodium hydroxide (NaOH), a strong base, releases hydroxide ions (OH-) when dissolved in water, making the solution basic.

The Brønsted-Lowry theory focuses on proton (H+) transfer. Acids are proton donors, while bases are proton acceptors.

In HCl's reaction with water, HCl acts as an acid by donating a proton (H+) to water, forming hydronium ion (H3O+) and chloride ion (Cl-).

Ammonia (NH3) acts as a base by accepting a proton (H+) from water, forming ammonium ion (NH4+) and hydroxide ion (OH-).

Every acid has a corresponding conjugate base, differing only by the presence or absence of a proton (H+).

HCl (an acid) and Cl- (its conjugate base) differ by a proton. When HCl loses a proton, it becomes Cl-

NH3 (a base) and NH4+ (its conjugate acid) differ by a proton. When NH3 gains a proton, it becomes NH4+

Strong acids ionize completely in solution, meaning they release all their hydrogen ions (H+) when dissolved in water.

Hydrochloric acid (HCl), sulfuric acid (H2SO4), and nitric acid (HNO3) are examples of strong acids.

Weak acids only partially ionize in solution, meaning they release only a portion of their hydrogen ions (H+) when dissolved in water.

Acetic acid (CH3COOH), found in vinegar, is a weak acid, releasing only a small fraction of its H+ in solution.

Strong bases ionize completely in solution, meaning they release all their hydroxide ions (OH-) when dissolved in water.

Sodium hydroxide (NaOH), potassium hydroxide (KOH), and barium hydroxide (Ba(OH)2) are examples of strong bases.

Weak bases only partially ionize in solution, meaning they release only a portion of their hydroxide ions (OH-) when dissolved in water.

Ammonia (NH3), a common household cleaning agent, is a weak base, releasing only a small fraction of its OH- in solution.