A base is a substance that can accept protons.

They have a pH reading of above 7.

In water, bases form OH- ions, meaning they react with acids to form water.

The Brønsted - Lowry theory of Acids and Bases[edit | edit source]

This states that acids are proton donors, while bases are proton acceptors which accept a proton (or hydrogen ion) from an acid.

Reactions[edit | edit source]

  • A neutralisation reaction is when a acid and a base react together to create a salt and water:

Base + Acid -> Water + Salt

This can be remembered as BAWS

Strong and Weak bases[edit | edit source]

The 'strength' of an base is whether it completely dissociates (or ionises) when dissolved in water (forming OH- ions) . Bases which totally dissociate are called strong bases, while ones where some molecules remain un-ionised are called weak bases.

Alkali[edit | edit source]

An alkali is a base that is able to dissolve in water. All alkalis are are bases, but not all bases are alkalis.
