Question

Is the reaction between quicklime and water endothermic or exothermic?

Answer 1

Quick lime is an inorganic compound that is made up of calcium and oxygen atoms. If the reactions occur and energy or heat is released then it will be categorized as an exothermic reaction and if the reactions occur when the energy is supplied or absorbed then it will be categorized as an endothermic reaction.

Complete answer:
We know that the reactions can be categorized on the basis of many factors, so energy or heat is a factor in which the reactions are divided into two, i.e., exothermic reactions and endothermic reactions. If the reactions occur and energy or heat is released then it will be categorized as an exothermic reaction and if the reactions occur when the energy is supplied or absorbed then it will be categorized as an endothermic reaction.
So, the reaction given in the question is between quick lime and water. Quick lime is an inorganic compound that contains calcium and oxygen. Is it chemically known as calcium oxide and its formula is $CaO$ and it is reacting with water whose formula is ${{H}_{2}}O$, so there is the formation of calcium hydroxide having a formula $Ca{{(OH)}_{2}}$.
The reaction is given below:
$CaO+{{H}_{2}}O\to Ca{{(OH)}_{2}}$
When the reaction occurs there is a release of a huge amount of energy, so it is categorized as an exothermic reaction. The energy released in this reaction is so large that it can even cause the water to boil, so it is highly exothermic.

Note:
We can also categorize the reaction of the formation of calcium hydroxide from calcium oxide and water as a combination reaction because there is only the formation of one product from two reactants.