For $[Pt (en) X_{2} Cl X_{2}] Cl X_{2}$ (en = neutral bidentate ligand; octahedral cation), which statements are correct? One or more options may be correct.

AThe cation has two stereoisomers.
BThe oxidation state of Pt is $+ 4$ and its coordination number is 6.
CIt furnishes 3 ions per formula unit and gives 2 mol of $AgCl$ per mole with excess $AgNO X_{3}$ .
DOne of the stereoisomers of the cation is optically active.

Answer: B, C, D

The two outer

Cl X^{-}

show the cation charge is

+ 2

, so

x - 2 = + 2

and Pt is

+ 4

; coordination number

2 \times 2 + 2 = 6

. Ions: one cation plus

2 Cl X^{-}

= 3, and 2 AgCl. The cation is

M (AA) X_{2} b X_{2}

with trans (achiral) and cis (chiral, 2 enantiomers) forms, i.e. 3 stereoisomers, so option 1 is false and option 4 is true.