Question

What are produced when a base is dissolved in water\[?\]

Answer 1

Hint: First we know what an acid and base is and how it is produced. After that when the base is dissolved in water it produces a conjugate base and conjugate acid. We have to find the conjugate acid.

Complete answer:
An acid can be defined as "any substance that, when dissolved in water, produces hydronium ions (\[{H_3}{O^ + }\])". Hydronium ions are produced when an \[{H^ + }\] ion from a proton donor reacts with water. For example, when hydrochloric acid is dissolved in water the following reaction occurs:
\[HCl(aq) + {H_2}O(l) \to {H_3}{O^ + }(aq) + C{l^ - }(aq)\]
Bases can be defined as "any substance that, when dissolved in water, generates hydroxide ions (\[O{H^ - }\])". Hydroxide ions are produced under two conditions. First, they are produced when an ionic compound containing hydroxide such as sodium hydroxide dissolves in water.
\[NaOH(s) \to N{a^ + }(aq) + O{H^ - }(aq)\]
Second, hydroxide ions are produced when a substance like ammonia accepts a proton from water.
\[N{H_3}(aq) + {H_2}O(l) \to N{H_4}^ + (aq) + O{H^ - }(aq)\]
When a base is dissolved in water dissociates to form a conjugate acid and conjugate base. The conjugate base and acid are ions. The conjugate base is stronger than the conjugate acid. Stronger the conjugate base stronger the base. Weak bases also have their conjugate bases with more strength than the conjugate acid but the difference between them is very less.
For example, the strong base NaOH dissociates to form
\[NaOH(s) + {H_2}O(l) \to N{H_4}^ + (aq) + O{H^ - }(aq)\]
Hence, when bases are dissolved in water, an excess of hydroxide ions (hydroxyls) is created.

Note:
Note that when acids are dissolved in water, an excess of hydronium is created. Also note that the concentration of hydroxide ions will increase when excess base is dissolved in a solution of sodium hydroxide because the amount of hydroxide ions per unit volume increases. This happens only when base added dissolves in water.