42. NCERT Exemplar XV

 

\(Pb(NO_3​)_2\)​(aq) + \(2KI\)(aq) → \(PbI_2\)​(s) + \(2KNO_3\)​(aq)\(PbI_2\)​(s) + \(2KNO_3\)​(g)\(PbI_2\)​(l) + \(2KNO_3\)​(s)\(PbI_2\)​(aq) + \(2KNO_3\)​(aq)

 

This is an example of exothermicendothermicprecipitationdecomposition and a double displacement reaction.

 

In the above reaction, solid lead iodide (\(PbI_2\)​) precipitates are formed. Hence, \(x\) represents the solid(s) form of lead iodide, and \(y\) represents potassium nitrate's aqueous (aq) form.

 

 

\(2FeSO_4\)​(s) \(\xrightarrow[]{Heat}\) \(Fe_2​O_3\)​(s) + \(SO_4\)​(g) + \(SO_3\)​(g)\(Fe_2​O_3\)​(s) + \(SO_3\)​(g) + \(SO_4\)​(g)\(Fe_2​O_3\)​(s) + \(SO_2\)​(g) + \(SO_3\)​(g)\(Fe_2​O_4\)​(s) + \(SO_2\)​(g) + \(SO_3\)​(g)

The decomposition of ferrous sulphate is an exothermicendothermicdecompositionprecipitation reaction because it includes heat absorption to generate ferric oxide (\(Fe_2​O_3\)), sulphur dioxide (\(SO_2\)), and sulphur trioxide (\(SO_3\)).