Question

Complete and balance the following equation:

$$\begin{gathered} {\mathrm{KNO}}_3\stackrel{\mathrm{heat}}{\to } \\ \mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\stackrel{\mathrm{heat}}{\to } \end{gathered}$$

Answer 1

• When potassium nitrate is heated it decomposes into potassium nitrite and oxygen.
• $\underset{\mathrm{potassium}\mathrm{nitrate}}{\underset{}{2{\mathrm{KNO}}_3\left(\mathrm{s}\right)}}\stackrel{\mathrm{heat}}{\to }\underset{\mathrm{potassium}\mathrm{nitrite}}{\underset{}{2{\mathrm{KNO}}_2\left(\mathrm{s}\right)}}+{\mathrm{O}}_2\left(\mathrm{g}\right)$
• Lead(II) nitrate on heating gives a brown gas NO₂ which undergoes dimerization on cooling to form dinitrogen tetraoxide N₂​O₄​.
• $\underset{\mathrm{lead}\left(\mathrm{II}\right)\mathrm{nitrate}}{\underset{}{2\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{s}\right)}}\stackrel{673K}{\to }\underset{\mathrm{nitrogren}\mathrm{dioxide}}{\underset{}{4{\mathrm{NO}}_2\left(\mathrm{g}\right)}}+\underset{\mathrm{lead}\mathrm{oxide}}{\underset{}{2\mathrm{PbO}\left(\mathrm{s}\right)}}+\underset{\mathrm{oxygen}}{\underset{}{{\mathrm{O}}_2\left(\mathrm{g}\right)}}$