Question

Write the balanced chemical equation for the following.

Nitric acid is added to Calcium carbonate

Answer 1

Part 1: Balanced chemical equation

1. The equation which contains an equal number of atoms on both sides of the reaction is known as balanced chemical equation.

Part 2: Steps for balancing

Step 1: Writing the chemical reaction

1. When we react Calcium carbonate with Nitric acid they produce Carbon dioxide, Water and Calcium nitrate as their products.
2. The unbalanced chemical equation is as follows:

$\underset{(\mathrm{Calcium}\mathrm{carbonate})}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}+\underset{(\mathrm{Nitric}\mathrm{acid})}{{\mathrm{HNO}}_3\left(\mathrm{aq}\right)}\to \underset{(\mathrm{Calcium}\mathrm{nitrate})}{\mathrm{Ca}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)}+\underset{(\mathrm{Carbon}\mathrm{dioxide})}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Step 2: Calculate the number of atoms on both sides of the unbalanced reaction.

1. To balance this equation we first identify the number of atoms on each side of the equation.
2. On the reactant side: 1 atom of Calcium, 1 atom of Carbon, and 3 atoms of Oxygen are used in Calcium carbonate $\mathbf{\left(}{\mathbf{CaCO}}_{\mathbf{3}}\mathbf{\right)}$.
3. Similarly, 1 atom of Hydrogen, 1 atom of Nitrogen, and 3 atoms of Oxygen are used in Nitric acid $\mathbf{\left(}{\mathbf{HNO}}_{\mathbf{3}}\mathbf{\right)}$.
4. On the product side: 1 atom of Calcium, 2 atoms of Nitrogen, and 6 atoms of Oxygen are used in $\mathbf{Ca}{\mathbf{\left(}{\mathbf{NO}}_{\mathbf{3}}\mathbf{\right)}}_{\mathbf{2}}$.
5. Similarly, Carbon dioxide contains 1 Carbon atom and 2 Oxygen atoms.
6. 2 Hydrogen atoms and 1 Oxygen atom are present in the Water molecule.

Step 3: To balance this equation we multiply 2 to Nitric acid.

1. The chemical reaction is as follows:

$\underset{(\mathrm{Calcium}\mathrm{carbonate})}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}+\underset{(\mathrm{Nitric}\mathrm{acid})}{2{\mathrm{HNO}}_3\left(\mathrm{aq}\right)}\to \underset{(\mathrm{Calcium}\mathrm{nitrate})}{\mathrm{Ca}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)}+\underset{(\mathrm{Carbon}\mathrm{dioxide})}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Step 4: Calculate the number of atoms on both sides of the balanced reaction

1. On the reactant side: 1 atom of Calcium, 1 atom of Carbon, and 3 atoms of Oxygen are used in Calcium carbonate
2. Similarly, 2 atom of Hydrogen, 2 atom of Nitrogen, and 6 atoms of Oxygen are used in Nitric acid.
3. On the product side: 1 atom of Calcium, 2 atoms of Nitrogen, and 6 atoms of Oxygen are used in Calcium nitrate
4. Similarly, Carbon dioxide contains 1 Carbon atom and 2 Oxygen atoms.
5. 2 Hydrogen atoms and 1 Oxygen atom are present in the Water molecule.

Now, we get the balanced equation in which the number of atoms on the reactant side is equal to the number of molecules on the product side.

$\underset{(\mathrm{Calcium}\mathrm{carbonate})}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}+\underset{(\mathrm{Nitric}\mathrm{acid})}{2{\mathrm{HNO}}_3\left(\mathrm{aq}\right)}\to \underset{(\mathrm{Calcium}\mathrm{nitrate})}{\mathrm{Ca}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)}+\underset{(\mathrm{Carbon}\mathrm{dioxide})}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}+\underset{\left(\mathrm{Water}\right)}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$