Question

State the type of reaction and balance the equation.

${\mathrm{Cl}}_2+\mathrm{KBr}\to \mathrm{KCl}+{\mathrm{Br}}_2$

Answer 1

The given reaction is a displacement reaction.

Displacement reaction - A reaction in which a more active element displaces a less active element from its solution, called displacement reaction.

Balancing the chemical equation -

• The unbalanced chemical equation must be obtained by writing the chemical formulae of the reactants and the products.
• Algebraic variables are assigned to each species (as stoichiometric coefficients) in the unbalanced chemical equation.
• The equations for each element are listed together to form a system of equations.
• Now that the smallest value of each variable is obtained, their values can be substituted into the chemical equation obtained.
• Traditional Method

Following the traditional method, the reaction can be balanced as follows:

Equation: ${\mathrm{Cl}}_2+\mathrm{KBr}\to \mathrm{KCl}+{\mathrm{Br}}_2$
Reactant Side	Product Side
2 chlorine atoms	1 chlorine atoms
1 Potassium atom	1 Potassium atom
1 Bromine atom	2 Bromine atom

• First, the chlorine atoms are balanced. The equation becomes ${\mathrm{Cl}}_2+\mathrm{KBr}\to 2\mathrm{KCl}+{\mathrm{Br}}_2$
• Now, the bromine atoms must be balanced, there is one bromine atom on the reactant side and 2 on the product side.
• Therefore, there must be 2 Br molecules on the reactant side. The chemical equation is transformed into ${\mathrm{Cl}}_2+2\mathrm{KBr}\to 2\mathrm{KCl}+{\mathrm{Br}}_2$
• Now the number of potassium is equal on both sides.

Therefore Balance equation is ${\mathrm{Cl}}_2+2\mathrm{KBr}\to 2\mathrm{KCl}+{\mathrm{Br}}_2$