Question

Balance each one of the following chemical equations:

$\mathrm{NaCl}+{\mathrm{AgNO}}_3\to \mathrm{AgCl}+{\mathrm{NaNO}}_3$

Answer 1

Step 1: Balanced chemical equations

Chemical equations are balanced by the trial and error method in which coefficients are added before each species to make the number of atoms on the reactant side equal to that on the product side. Therefore, balanced equations obey the law of conservation of mass.

Step 2: Reaction between Sodium chloride and Silver nitrate

Aqueous solutions of sodium chloride $\left(\mathrm{NaCl}\right)$ and silver nitrate $\left({\mathrm{AgNO}}_3\right)$ react to form solid silver chloride $\left(\mathrm{AgCl}\right)$ and sodium nitrate $\left({\mathrm{NaNO}}_3\right)$. The equation is an example of a precipitation reaction because a precipitate of silver chloride gets formed.

The equation for the reaction is:

$\mathrm{NaCl}+{\mathrm{AgNO}}_3\to \mathrm{AgCl}+{\mathrm{NaNO}}_3$

The number of atoms of each element is given as:

Element	Reactant side	Product side
Na	1	1
Cl	1	1
Ag	1	1
N	1	1
O	3	3

Step 3: Balancing atoms on both sides

The number of atoms of all the elements are the same on both sides. Therefore, the reaction is balanced.

The balanced equation for the reaction is:

$$\begin{gathered} \mathrm{NaCl}\left(\mathrm{aq}\right)+{\mathrm{AgNO}}_3\left(\mathrm{aq}\right)\to \mathrm{AgCl}\left(\mathrm{s}\right)+{\mathrm{NaNO}}_3\left(\mathrm{aq}\right) \\ \left(\mathrm{sodium} \\ \mathrm{chloride}\right)\left(\mathrm{silver}\mathrm{nitrate}\right)\left(\mathrm{silver} \\ \mathrm{chloride}\right)\left(\mathrm{sodium}\mathrm{nitrate}\right) \end{gathered}$$