Question

Balance each of the following chemical equations given below:
A.$FeC{l_3} + N{H_4}OH \to N{H_4}Cl + Fe{\left( {OH} \right)_3}$
B.$KI + C{l_2} \to KCl + {I_2}$

Answer 1

We know that a balanced chemical equation contains the same number of atoms for each element that takes place in the chemical reaction. We have to calculate the number of atoms for a given element by multiplying the coefficient of any formula having that element by the subscript of the element in the formula. If we notice an element is seen in more than one formula on a given side of the equation, we have to compute the number of atoms and then add them together.

Complete step by step answer:
1.The given chemical equation is,
$FeC{l_3} + N{H_4}OH \to N{H_4}Cl + Fe{\left( {OH} \right)_3}$
-The reaction of ferric chloride with ammonium hydroxide is an example of double displacement reaction.
-Ferric chloride reacts with ammonium hydroxide to form ammonium chloride and ferric hydroxide. The chemical reaction is,
$FeC{l_3} + N{H_4}OH \to N{H_4}Cl + Fe{\left( {OH} \right)_3}$ (Unbalanced)
-Place a coefficient 3 in front of ${\text{N}}{{\text{H}}_{\text{4}}}{\text{OH}}$ and ${\text{N}}{{\text{H}}_{\text{4}}}{\text{Cl}}$ to balance ammonium atoms and chlorine atoms on both product and reactant side.
-All the other atoms are balanced.
We can write the balanced equation as,
$FeC{l_3} + 3N{H_4}OH \to 3N{H_4}Cl + Fe{\left( {OH} \right)_3}$ (Balanced)
-Each side comprises $1Fe$,$3N$,$15H$,$3Cl$,$3O$ atoms.
2.The given chemical equation is,
$KI + C{l_2} \to KCl + {I_2}$
-The reaction of potassium iodide with chlorine is an example of single displacement reaction.
Potassium iodide reacts with chlorine to form potassium chloride and iodine as products. The chemical reaction is,
$KI + C{l_2} \to KCl + {I_2}$ (Unbalanced)
Place a coefficient 2 in front of $KI$ to balance potassium and iodine atoms in the reactant side.
The equation becomes,
$2KI + C{l_2} \to KCl + {I_2}$ (Unbalanced)
-The unbalanced potassium and chlorine in the product side is balanced by placing a coefficient 2 before $KCl$
$2KI + C{l_2} \to 2KCl + {I_2}$ (Balanced)
Each side comprises $2K$,$2Cl$,$2I$ atoms.

Note:
Based on the law of conservation of mass, matter cannot be created or destroyed. Therefore, the mass of the products in a chemical reaction is equal to mass of the reactants. The purpose of balancing chemical equations is to have the same number of each type of element on each side of a chemical equation. Balancing chemical equations also helps to determine the stoichiometric relationship between the substances/elements/compounds.