Question

Name the type of the reaction between quick lime and water giving calcium hydroxide.

Answer 1

Step 1: Chemical reaction

A chemical reaction is a process in which one or more substances (reactants) are converted into new substances (products) by the formation and breaking of chemical bonds. Chemical reactions are divided into different types based on the nature of the products formed or the nature of the process of the reaction. Some of the types of reactions include combination reactions, decomposition reactions, displacement reactions, etc.

Step 2: Reaction between quick lime and water

Quick lime is chemically known as calcium oxide $\left(\mathrm{CaO}\right)$. When water $\left({\mathrm{H}}_2\mathrm{O}\right)$ is added to quick lime, calcium hydroxide $\left[\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\right]$ is formed, which is called slaked lime. The balanced equation of the reaction is:

$$\begin{gathered} \mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to \mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{s}\right) \\ \mathrm{Calcium}\mathrm{Water}\mathrm{Calcium}\mathrm{hydroxide} \\ \mathrm{oxide} \end{gathered}$$

In this reaction, calcium oxide and water combine to form calcium hydroxide. Reactions in which two or more reactants form a single product are called combination reactions. Combination reactions involve the formation of new bonds and therefore are exothermic. A large amount of heat is produced during the formation of slaked lime.

Therefore, the formation of slaked lime is an example of a combination reaction.