QJEEM23Ch7f4c: JEE Main 2023 Chemistry - Class 12 JEEM23Ch7f4c Solution: Which one of the following is not an example of calcination?

Calcination is the process of heating a solid material in the absence of air or with limited air to remove volatile components or to cause thermal decomposition. Among the given reactions:

(A) $\mathrm{CaCO}_3 \cdot \mathrm{MgCO}_3 \stackrel{\Delta}{\longrightarrow} \mathrm{CaO}+\mathrm{MgO}+2 \mathrm{CO}_2$ is an example of calcination, where a mixture of calcium carbonate and magnesium carbonate is heated to produce calcium oxide, magnesium oxide, and carbon dioxide.

(C) $\mathrm{CaCO}_3 \stackrel{\Delta}{\longrightarrow} \mathrm{CaO}+\mathrm{CO}_2$ is an example of calcination, where calcium carbonate is heated to produce calcium oxide and carbon dioxide.

(D) $\mathrm{Fe}_2 \mathrm{O}_3 \cdot \mathrm{xH}_2 \mathrm{O} \stackrel{\Delta}{\longrightarrow} \mathrm{Fe}_2 \mathrm{O}_3+\mathrm{xH}_2 \mathrm{O}$ is an example of calcination, where hydrated iron(III) oxide loses water molecules to form anhydrous iron(III) oxide.

However, (B) $2 \mathrm{PbS}+3 \mathrm{O}_2 \stackrel{\Delta}{\longrightarrow} 2 \mathrm{PbO}+2 \mathrm{SO}_2$ is not an example of calcination. This reaction is an example of roasting, a process in which a sulfide ore is heated in the presence of air to convert it into its oxide and release sulfur dioxide gas. Roasting is typically used for metal extraction from sulfide ores.

So the correct answer is:

(B) $2 \mathrm{PbS}+3 \mathrm{O}_2 \stackrel{\Delta}{\longrightarrow} 2 \mathrm{PbO}+2 \mathrm{SO}_2$