A table of these properties is shown here which distinguishes acids and bases apart from one another by some of their easily observed chemical and physical properties.
| Acid | Base | |
| Definition
Arrhenius Definition: |
An acid is any chemical compound which when dissolved in water gives a solution with a hydrogen ion activity greater than in pure water. | A base is an aqueous substance that can accept hydrogen ions. |
| Bronstead Lowry Definition: | An acid is an substance which donates a proton. | A base is any substance which accepts a proton. |
| Physical characteristics | Depending on the temperature, acids can occur in solid, liquid or gaseous form. Taste sour. | Bases feel slippery because of the reaction of the base with the oils of your hand. Frequently solids except ammonia which is a gas. Taste bitter. |
| Phenolphthalein | colorless | pink |
| Strength | depends on concentration of the hydronium ions | depends on concentration of the hydroxide ions |
| Dissociation | Acids free hydrogen ions (H+) when mixed with water. | Bases free hydroxide ions (OH-) when mixed with water. |
| Chemical Formula | An acid has a chemical formula with H at the beginning of it. There is one exception to his rule, CH3COOH = Acetic Acid (vinegar) | A base has a chemical formula with OH at the end of it |
| Litmus test | Acids change litmus paper red. | Bases change litmus paper blue. |
| Examples | Acetic acid i.e.CH3COOH and Sulfuric acid | Sodium Hydroxide (NAOH) and Ammonia (NH3) |
