4 Cr—O bonds are equivalent

6 Cr—O bonds are equivalent

all Cr—O bonds are equivalent

all Cr—O bonds are equivalent

Fused mixture of ${\rm{A}}{{\rm{g}}_2}{\rm{S}}$ and KCl is electrolysed

${\rm{A}}{{\rm{g}}_2}{\rm{S}}$ is reduced with CO

${\rm{A}}{{\rm{g}}_2}{\rm{S}}$ is roasted to ${\rm{A}}{{\rm{g}}_2}{\rm{O}}$ which is reduced with C

Treating with NaCN solution followed by metal displacement with zinc

Green salt

Glauber’s salt

Mohr’s salt

Alum

Pt

Fe

W

Cu

${\rm{CuS}}{{\rm{O}}_4}.7{{\rm{H}}_2}{\rm{O}}$

${\rm{ZnS}}{{\rm{O}}_4}.7{{\rm{H}}_2}{\rm{O}}$

${\rm{CuS}}{{\rm{O}}_4}.5{{\rm{H}}_2}{\rm{O}}$

${\rm{FeS}}{{\rm{O}}_4}.7{{\rm{H}}_2}{\rm{O}}$

${\rm{ZnO}}$

${\rm{HgO}}$

${\rm{A}}{{\rm{g}}_2}{\rm{O}}$

${\rm{CuO}}$

Chromate ions are reduced.

Chromate ions are oxidised.

Mono centric complex is converted into dicentric complex.

Oxygen gets removed from chromate ions.

($n - 1)\;d -$orbitals

($n - 2)\;f$-orbitals

($n - 1)\;d$-orbitals and ($n -$1) $f$-orbitals

($n - 1)\;d$-orbitals and $ns -$orbitals

Complete $d$-subshell

Inert pair effect

$4{s^2}$-subshell

None of these

${\rm{S}}{{\rm{O}}_2}{\rm{\;and\;S}}{{\rm{O}}_3}$

${\rm{S}}{{\rm{O}}_2}$ only

${\rm{S}}{{\rm{O}}_3}$ only

S only

Tin

Zinc

Mercury

Calcium