Question

In the decomposition of Lead (II) Nitrate to give lead (II) oxide, Nitrogen dioxide, and Oxygen gas, the coefficient of Nitrogen dioxide in the balanced equation is

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is D

4

The explanation for the correct answer

Option (D) 4

Steps in balancing a chemical equation:

• First, count each type of atom in reactants and products present in the reaction, if the same number of each atom appears on both sides of the arrow then the reaction is balanced.
• If not, then place coefficients, as needed, in front of the symbols or formulas to increase the number of atoms or molecules of the substances. (try to use the smallest coefficients possible).
• Change only the coefficients, never change the subscripts in chemical formulas changing subscripts changes the substances involved in the reaction.
• Repeat this until the equation is balanced.

Balanced equation:

• The symbolic representation of a chemical reaction is the chemical equation.
• In a balanced chemical equation, the number of atoms of each element will be the same on both sides of the reaction.
• Decomposition reactions can be defined as the reactions in which a single reactant is broken into two or more products.$\left(\mathrm{AB}\to \mathrm{A}+\mathrm{B}\right)$
• The chemical equation for the decomposition of Lead (II) nitrate to give Lead (II)oxide, Nitrogen dioxide, and oxygen is;
  $\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{s}\right)\to \mathrm{PbO}\left(\mathrm{s}\right)+{\mathrm{NO}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$
• In order to get the balanced chemical equation, we have to multiply $\mathrm{PbO}$ and $\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2$ by the factor of 2 and ${\mathrm{NO}}_2$ by the factor of 4.
• Then the equation becomes

$2\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{s}\right)\to 2\mathrm{PbO}\left(\mathrm{s}\right)+4{\mathrm{NO}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$

• Thus the coefficient of nitrogen dioxide in the decomposition of Lead (II) nitrate is 4.
• Hence, correct option.