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

$(i)$ Every mineral is an ore but every ore is not a mineral

$(ii)$ Slag is product formed during extraction of metal by combination of flux and impurities.

$(iii)$ Highly pute metals can be obtained by zone refining.

$(iv)$ Carnallite is an ore of magnesium and sodium.

Leaching of $Ag_2S$ is carried out by heating it with a dilute solution of

Silica is added to roasted copper ores during extraction in order to remove

Neutral refractory material used in furnaces is

$20\,mL$ of $0.5\,M\,NaCl$ is required to coagulate $200\,mL$ of $As _2 S _3$ solution in $2$ hours. The coagulating value of $NaCl$ is $………..$.