Question

What happens when calcium nitrate is heated?

Answer 1

Hint: As we know, the chemical formula of calcium nitrate is $$Ca{\left(N{O}_3\right)}_2$$. It is a form of inorganic double salt. This salt is generally found as colorless. It is crystalline in structure. When any substance is heated, it undergoes thermal decomposition.

Complete step by step answer:
Let’s first find out what calcium nitrate is and its uses.
Calcium nitrate is the main component in fertilizers. It has the ability to absorb moisture from the air. Thus, commonly, it is found as tetrahydrate.
Now, let’s find out the process of heating calcium nitrate. We can observe that when calcium nitrate is heated, it can produce two gases and a solid product. When calcium nitrate is heated, it undergoes thermal decomposition, i.e. it breaks down into calcium oxide, nitrogen dioxide and oxygen gas. The chemical reaction is given below:
$$2Ca{\left(N{O}_3\right)}_2\stackrel{\mathrm{\Delta }}{\to }2CaO+4N{O}_2\uparrow +O_2\uparrow$$
This chemical equation is balanced since the number of elements in the reactant side is equal to that in the product side. Here, $CaO$ is the calcium oxide and $N{O}_2$ is the nitrogen dioxide. Nitrogen dioxide has a reddish brown color. While the calcium oxide has a white color. Nitrogen dioxide generally forms fumes.
This is an example of decomposition reaction. In a decomposition reaction, the molecule breaks down into two or more products and heat is taken as a form of energy.
An arrow mark is put near nitrogen dioxide and oxygen molecules. It shows that these gases, i.e. nitrogen dioxide and oxygen gases, are evolved during the thermal decomposition reaction.

Note: There is a reddish brown fumes which is released which is the nitrogen dioxide gas. But we do not tell anything specific about oxygen gas since the oxygen gas is a transparent gas molecule. A similar reaction occurs when copper nitrate is heated. It produces copper oxide, nitrogen dioxide and oxygen gas.