Identify the type of chemical reaction taking place and also write the balanced chemical equation for : Quicklime reacts vigorously (very fast) with water releasing a large amount of heat.

When $CaO$ (quicklime) is added to water, a large amount of heat is produced with the formation of Calcium Hydroxide $Ca(OH{)}_2$

This is a Combination Reaction.

Chemical equation of the reaction:-

$\underset{CalciumOxide}{CaO}\left(s\right)+\underset{Water}{H_{2}O}\left(l\right)⟶\underset{CalciumHydroxide}{Ca(OH{)}_2}$

$\left(quicklime\right)$