Question

A reddish brown gas is released on heating lead nitrate. The type of reaction involved here is:

• A. combination reaction
• B. displacement reaction
• C. decomposition reaction
• D. double displacement reaction

Answer 1

The correct option is C decomposition reaction

A decomposition reaction is where one reactant is broken into multiple simple products.

When lead nitrate $\left(2\text{Pb}{\text{(NO}}_3{)}_2\right)$ is heated, it decomposes into lead oxide $\left(\text{PbO}\right)$, nitrogen dioxide $\left({\text{NO}}_2\right)$ and oxygen $\left({\text{O}}_2\right)$. The reaction occurs as follows:
$2\text{Pb}{\text{(NO}}_3{)}_2\text{(s)}\stackrel{\text{Heat}}{⟶}2\text{PbO (s)}+4{\text{NO}}_2\text{(g)}+{\text{O}}_2\text{(g)}$

The reddish brown gas released is ${\text{NO}}_2$.