Question

$ CaO{\text{ }} + {\text{ }}{H_2}O{\text{ }} \to Ca{\left( {OH} \right)_2} $ is an example of which reaction?

Answer 1

Hint :A chemical reaction is a process that results in the chemical change of one set of chemical substances into another set of chemical substances. Chemical reactions are often defined as changes in the locations of electrons in the formation and breaking of chemical bonds between atoms, with no change in the nuclei (no change in the elements present), and may be represented using a chemical equation.

Complete Step By Step Answer:
A combination reaction is a reaction in which two or more elements or compounds (reactants) combine to generate a single chemical (product). Equations of the type $ X{\text{ }} + {\text{ }}Y \to {\text{ }}XY $ are used to depict such reactions. A combination reaction is when two or more components are combined to produce a single compound. To put it another way, when two or more elements or compounds react to generate a single compound, the chemical reaction is known as a combination reaction. Exothermic reactions are those in which heat is emitted as a result of the formation of a bond between the reactants. The outcome of a combination reaction between a metal and a non-metal is an ionic solid. Lithium interacting with sulphur to form lithium sulphide is one example. When magnesium is burned in the presence of oxygen, the metal's atoms unite to form magnesium oxide. Flares emit a brilliant flame as a result of this precise combo reaction.
Now here,
 $ CaO{\text{ }} + {\text{ }}{H_2}O{\text{ }} \to Ca{\left( {OH} \right)_2} $
This is a combination reaction, where calcium oxide and water combine to generate calcium hydroxide, a single result.

Note :
Calcium hydroxide is a chemical substance that is made up of inorganic elements. When quicklime (calcium oxide) is combined or slaked with water, it produces a colourless crystal or white powder. Hydrated lime is also known as caustic lime, builders' lime, slack lime, cal, and pickling lime. A saturated solution of calcium hydroxide is known as lime water.