Mercury cathode can not be used for alkali metals in their fused state because

$Ag_2S + NaCN + Zn \rightarrow Ag$

This method of extraction of $Ag$ by complex formation and then its displacement is called :

Give the correct order of initials $T$ or $F$ for following statements. Use $T$ if statement is true and $F$ if it is false.

$(i)$ $Cu$ metal is extracted from its sulphide ore by reduction of $Cu_2O$ with $FeS.$

$(ii)$ An ore of Tin containing $FeCrO_4$ is concentrated by magnetic separation method.

$(iii)$ Auto reduction process is used in the extraction of $Cu\, \& \,Hg.$

$(iv)$ Cassiterite and Rutile are oxide ores of the metals.

The process, which does not use a catalyst is

The correct statements are :