What is a base?

In chemistry, a base is a substance that can accept protons or donate electrons. Bases are typically slippery to the touch, have a bitter taste, and can turn red litmus paper blue. They are the opposite of acids and can neutralize acids to form salts and water. Examples of bases include sodium hydroxide (NaOH), ammonia (NH3), and magnesium hydroxide (Mg(OH)2).

Chemical Definition:

A base is a substance that:

- Donates electrons or protons (H+ ions): Bases react with acids to form salts and water.
- Increases pH when dissolved in water: Bases have a pH greater than 7.
- Feels slippery to the touch: Bases often contain hydroxide (OH-) ions, which give them a slippery feel.

Properties of Bases:

- Corrosive: Strong bases can cause burns and skin irritation.
- React with acids: Bases neutralize acids, forming salts and water.
- Dissolve in water: Most bases dissolve in water to form ions.
- Change the color of indicators: Bases turn litmus paper blue and phenolphthalein indicator pink.

Types of Bases:

1. Strong Bases:

- Ionize completely in water, releasing hydroxide (OH-) ions.
- Have a high pH (usually >12).
- Examples: Sodium hydroxide (NaOH), Potassium hydroxide (KOH)

2. Weak Bases:

- Ionize partially in water, releasing fewer hydroxide ions.
- Have a lower pH (typically between 7 and 12).
- Examples: Ammonia (NH3), Pyridine (C5H5N)

3. Neutral Bases:

- Do not ionize in water and do not affect pH.
- Examples: Acetic acid (CH3COOH), Sodium bicarbonate (NaHCO3)