Which of the following complex ions has a magnetic moment same as $[Cr(H_2O)_6]^{3+}$?

For the octahedral complexes of $Fe^{3+}$ in $SCN^{-}$ (thiocyanato-$S$) and in $CN^{-}$ ligand environments,the difference between the spin-only magnetic moments in Bohr magnetons (when approximated to the nearest integer) is
[Atomic number of $Fe = 26$]

The spin-only magnetic moments of the complexes $[Mn(CN)_6]^{3-}$ and $[Co(C_2O_4)_3]^{3-}$ are respectively:

Which one of the following does not exhibit geometrical isomerism?

Given below are two statements:
Statement $I$: $A$ homoleptic octahedral complex,formed using monodentate ligands,will not show stereoisomerism.
Statement $II$: $cis-$ and $trans-$ platin are heteroleptic complexes of $Pd$.
In the light of the above statements,choose the correct answer from the options given below.

$26.7 \ g$ of a compound with the formula $PtCl_2Br_2 \cdot 6H_2O$ is taken for analysis. This compound exhibits stereoisomerism,and a total of $3$ stereoisomers exist. Find the loss in mass (in $g$) when the given amount of the compound is treated with concentrated $H_2SO_4$. (Molar mass: $PtCl_2Br_2 \cdot 6H_2O = 534 \ g \ mol^{-1}$)