Acids and Bases Theories

Arrhenius Theory

Acids have H+

Bases have OH-

Phosphoric Acid→ H3PO4→ 3H+ + PO43-

Problem with Arthenius Theory

Many examples of compounds without OH- or H+ that are basic or acidic when dissolved in water.

AlCl3- Acidic Solution

Na2CO3- Basic Solution

H+

Does not exist in solution as it is too small

Binds with water to form hydronium ion

Moddified Arrhenius Theory

Instead of having a free H+ in a solution, a reaction occurs between the acid or base and water

HCl+ H2O → H3O+ CL-

CO3 + H2O → OH- + HCO3-

Moddified Arhenius Rules

1. If the compound is ionic, you must dissociate (pull apart) it

2. Take the ion that will make the acid H3O or base when reacted with water (ignore the other ion)

Bronsted- Lowry Acid Base Theory

Brønsted and Lowry were two scientists who independently studied acids and bases. They published their theories at the same time, and they were published together.

The Theory describes the actions of an acid and a base during a chemical reaction.