Unit: Acids, Bases, and Solutions Day 1 - Notes Unit: Acids, Bases, and Solutions Acids and Bases: Definitions, Properties and Characteristics

After today you will be able to… Define an acid and base according to the Arrhenius definition Describe and list properties that pertain to acids and bases Differentiate between strong and weak acids/bases Define an acid and base according to the Bronsted Lowry definition

There are three different types of definitions for acids and bases, but for our purposes we will only work with two. The Arrhenius definition and the Bronsted-Lowry definition.

Arrhenius Acids An Arrhenius acid is an ionic compound containing hydrogen that ionizes to form H+ ions. Acids have a sour taste (Ex: citric acid) Acids will cause indicators to change colors

Indicators: Are substances that change color based on pH.

Arrhenius Acids Turn litmus paper pink or red The pH of acids is less than 7 Acids will react with bases in a double replacement reaction called neutralization.

Arrhenius Acids  

Arrhenius Bases An Arrhenius base is an ionic compound containing hydrogen and oxygen, that dissociates to release OH- ions in solution. Bases have a bitter taste Bases are slippery (Ex: soap) Bases will cause indicators to change colors

Arrhenius Bases Bases change litmus paper blue. The pH of bases is greater than 7. Bases will react with acids (neutralization)

The strength of an Arrhenius acid or base is determined by the extent to which the acid or base ionizes or dissociates in solution.

Acid/Base Strength

Acid/Base Strength

Bronsted-Lowry Acids  

Bronsted-Lowry Bases  

 

B.L. Acid-Base Reactions A conjugate base is what remains after the acid has lost a proton H+

B.L. Acid-Base Reactions A conjugate acid is what is formed when a base gains a proton H+

B.L. Acid-Base Reactions In general, B.L. acid-base reactions are equilibrium systems meaning that both the forward and reverse reactions occur. They involve two acid-base pairs known as conjugate acid-base pairs.

B.L. Acid-Base Reactions An Amphoteric species (such as water) is one that can act as an acid or a base, depending on the strength of the acid or base with which it is reacting. Water acts as a base when reacting with a stronger acid. Water acts as an acid when reacting with a weaker acid.

Questions? Begin WS1