Explain the similarity and difference in two events, namely adding NaOH to water and adding CaO to water.

Explanation

Similarity:
(i) Both naOH and CaO dissolve in water. NaOH dissolves in water forming aqueous NaOH while CaO reacts with water to form Calcium Hydroxide `[Ca(OH)_(2)]`
(ii) Both are bitter in taste, and turn red litmus to blue. i.e. both are basic in nature.
`NaOH _((s))+H_(2)O_((l))to NaOH _((aq))+`Heat
`CaO_((s))+H_(2)O_((l))to Ca(OH)_(2(aq))+` Heat
Both are exothermic reactions.
(iii) After adding water, the properties of aqueous solution of sodium hydroxide (NaOH) and aqueous solution of calcium oxide (CaO) are different.
Difference:
(i) Sodium Hydroxide (NaOH) is highly soluble in water, whereas calcium oxide (CaO) is less soluble in water.
(ii) Aqueous solution of NaOH is monovalent, whereas aqueous solution of `Ca(OH)_(2)` is divalent.
(iii) As NaOH is highly soluble in water, makes strong base whereas `Ca(OH)_(2)` is a wak base.