Question

When quick lime is added to water a hissing sound is produced. Write the chemical reaction and name the type of reaction taking place.

Answer 1

Hint:As we know that the quick lime is also known as calcium oxide or burnt lime. The molecular formula of quick lime is $CaO$. Quick lime is a very important compound. It is used in production of iron, steel , paper and pulp production, treatment of water and mining industries.

Complete step by step solution:
Whenever we add quicklime or calcium oxide in water a hissing sound is produced. The chemical reaction can be written as : $CaO + {H_2}O \to Ca{(OH)_2}$. We can see that calcium hydroxide is formed in this reaction. Calcium hydroxide is also known as slaked lime. This reaction produces lots of heat . So it is an exothermic reaction. The heat produced in this reaction is so high that it can even boil water. We can observe that two compounds react to form only one compound . This type of reaction is known as combination reaction.
Slaking of lime is both a combination reaction and an exothermic reaction.

Note:
 Calcium hydroxide or $Ca{(OH)_2}$ is a very strong base. So it’s $pH$ will always be in between $7$ and $14$. It is a very useful compound. It is used in the Kraft process to convert wood into wood pulp. It is also used in the plastic industries to produce plastics.
When quick lime is added to water a hissing sound is produced due to the reaction : $CaO + {H_2}O \to Ca{(OH)_2}$. It is an exothermic reaction because a lot of heat is produced in this reaction . Two compounds react in this reaction to produce one single compound so it is a combination reaction.