Acids and Bases — Properties & Examples

Acids and Bases

• Acids are typically known as substances/compounds that have a pH less than 7

• Bases are typically known as substances/compounds that have a pH greater than 7

Brønsted-Lowry Acids and Bases:

• Defines acids and bases by whether they are a proton donor or acceptor

• Brønsted-Lowry Acids are proton (H+) donors, so they lose a proton in a reaction to "donate" the proton to the base

• Brønsted-Lowry Bases are proton (H+) acceptors, so they gain a proton in a reaction from the acid

Arrhenius Acids and Bases:

• Arrhenius acids and bases are defined by what is formed when the acid or base is dissociated in water

• Arrhenius acids and bases must contain either a hydrogen (acid, such as HCl) or OH (base, such as NaOH)

• Arrhenius acids are when if they are dissociated in water, they produce hydronium ions ($H_{3}O$+), this is because the hydrogen ion attach themselves to the water molecules in aqueous solutions, producing hydrodium ions

• Arrhenius bases are when if they are dissociated in water, they produce hydroxide ions (OH-)

Lewis Acids and Bases

• Lewis acids and bases are defined by whether they are an electron pair acceptor or donor

• Lewis acids are electron pair acceptors, so they accept a pair of nonbonding valence electrons from the lewis base

• Lewis bases are electron pair donors, so they donate a pair of their nonbonding valence electrons

(Video) Acid-Base Reactions in Solution: Crash Course Chemistry #8

by CrashCourse

In this video, Hank describes acids and bases. You'll learn the common definition for each, some standard conventions, and revisit stoichiometry. Hank also talks about how coal power plants cause acid rain. It's a direct application of what we're learning!