Chromium is obtained by reducing concentrated chromite ore with

Consider the following reactions at $1000\,^oC$

$(I)$  $Zn(s){\mkern 1mu}  + {\mkern 1mu} 1/2{\mkern 1mu} {O_2}(g){\mkern 1mu} \xrightarrow{\Delta }{\mkern 1mu} ZnO(g){\mkern 1mu} ;$      $\Delta {G^o}{\mkern 1mu}  = \,{\mkern 1mu}  – \,{\mkern 1mu} 360\,{\mkern 1mu} {\mkern 1mu} kJ{\mkern 1mu} \,{\mkern 1mu} mo{l^{ – 1}}$

$(II)$  $C(s){\mkern 1mu}  + {\mkern 1mu} 1/2{\mkern 1mu} {O_2}(g){\mkern 1mu} \xrightarrow{\Delta }{\mkern 1mu} CO(g){\mkern 1mu} ;$      $\Delta {G^o}{\mkern 1mu}  = {\mkern 1mu}  – \,{\mkern 1mu} 460{\mkern 1mu} {\mkern 1mu} \,kJ{\mkern 1mu} {\mkern 1mu} mo{l^{ – 1}}$

and choose the correct statement at $1000\,^oC$

Froth floatation is based upon

Read the following statements :

$(I)$ $Al$ has greater affinity than that of $Cr$ , for oxygen

$(II)$ $Al$ can be used for reduction of $Fe_2O_3$

$(III)$ Carbon is used for reduction of $PbO$

$(IV)$ $SnO_2$ can be reduced by carbon

Choose the correct set of statement $(s)$

The method used for the purification of Indium is ….. .