Which of the following metals is obtained by the leaching process using a solution of $NaCN$ and then precipitating the metal by the addition of zinc dust?

At a site,low grade copper ores are available and zinc and iron scraps are also available. Which of the two scraps would be more suitable for reducing the leached copper ore and why?

Which one of the following organizations' iron and steel plant was built to use charcoal as a source of power,to start with,but later switched over to hydroelectricity?

$Ni$ anode is used in the electrolytic extraction of

In the commercial electrochemical process for aluminium extraction,the electrolyte used is

In the metallurgical process of aluminium,cryolite $(Na_3AlF_6)$ is mixed with alumina $(Al_2O_3)$ in its molten state,because it