Question

Assertion (A) : Metals in the middle of activity series are found in nature as sulphides or carbonates. Reason (R) : The sulphide ores are calcinated whereas carbonate ores are roasted to extract metals from them.

Assertion (A): Metals low in the reactivity series are very unreactive. The oxides of these metals can be reduced to metals by heating alone. Reason (R): Cinnabar when heated in air first gets converted into mercuric oxide which is then reduced to mercury on further heating.

A metallurgist heats zinc sulphide in the presence of excess air and notices a white solid forming along with a gas that smells like a burning matchstick.

With the help of suitable chemical equations, list the two main differences between roasting and calcination. How is metal reduced from the product obtained after roasting/calcination of the ore ? Write the chemical equation for the reaction involved.