Question

Which of the following statements is wrong?

(a) During smelting, flux is used to remove gangue as slag

(b) The slag formed during smelting has low melting point and is heavier than metal

(c) Calcination of ore is carried out without the presence the oxygen

(d) Roasting is carried out in the presence of oxygen

I got this question by my school principal while I was bunking the class.

Query is from Extraction of Crude Metal from Concentrated Ore topic in section General Principles and Processes of Isolation of Elements of Chemistry – Class 12

Answer 1

The correct option is (b) The slag formed during smelting has low melting point and is heavier than metal

The explanation: Smelting is the process of extraction of a metal from its oxide by reduction with carbon (coke). Alkali metals, alkaline earth metals, etc. cannot be prepared by reduction of their respective oxides with carbon. The slag formed during smelting has high melting point and is lighter than the metal.