What are Strong Bases?

A strong base is a fully ionic substance such as sodium hydroxide or potassium hydroxide. In solution, the molecule can be thought of as being completely broken up into metal ions and hydroxide ions. Each mole of sodium hydroxide in solution dissolves to produce a mole of hydroxide ions.

NaOH ⇢ Na⁺ + OH^–

Some strong bases, such as calcium hydroxide, aren’t very water-soluble. It makes no difference; whatever does dissolve is completely ionised into calcium and hydroxide ions. Because of its 100% ionisation, calcium hydroxide is nevertheless considered a strong base.

Calculating the pH of a strong base as,

pH = – log10 [H⁺]

How can a solution containing hydroxide ions have a pH since pH is a measure of hydrogen ion concentration? To understand this, you must first understand the ionic product for water. Wherever there is water, a balance is established. The following is a simplified version of this equilibrium:

H₂O (l) ⇌ H⁺ (aq) + OH

With the addition of extra hydroxide ions, such as sodium hydroxide, the equilibrium still exists, but the point of equilibrium has shifted to the left, according to Le Chatelier’s Principle. Although there will be significantly fewer hydrogen ions than in pure water, hydrogen ions will still be present. The concentration of these is measured by the pH.

A description of how to calculate the pH of a strong base,

• Work out the concentration of the hydroxide ions.
• Use K_w to work out the hydrogen ion concentration.
• Convert the hydrogen ion concentration to a pH

Examples of Strong Bases

Some Examples of the Strong Bases are,

• Potassium Hydroxide (KOH)
• Sodium Hydroxide (NaOH)
• Barium Hydroxide (Ba(OH)₂)
• Caesium Hydroxide (CsOH)

The citric acid in fruits like oranges and lemons, tartaric acid in tamarind, malic acid in apples, lactic acid in milk and milk products, and hydrochloric acid in gastric juices are just a few examples of acids and bases found in nature. Many bases, such as lime water, can also be found. Many of these acids are used in our daily lives, such as vinegar or acetic acid in the kitchen, boric acid in laundry, baking soda in cooking, washing soda in cleaning, and so on.

Many acids and bases that we do not use in our daily lives are utilised in laboratories and industries, such as HCl, H₂SO₄, and NaOH, KOH, among others. The neutralisation process results in the creation of salt and water when these acids and bases are mixed in the proper quantities.