Question

How many stereoisomers are possible for tetrahedral [NiCl2Br2]2–?

Answer 1

No stereoisomers are possible for tetrahedral `["NiCl"_2"Br"_2]^(2-)`.

Explanation:

The only possible stereoisomer of a tetrahedral ion or molecule is its nonsuperimposable mirror image (enantiomer).

A tetrahedral molecule or ion must have four different atoms or groups attached to the central atom to be chiral and exist as a pair of enantiomers.

`["NiCl"_2"Br"_2]^(2-)` has two `"Br"` atoms and two `"Cl"` atoms attached to the central `"Ni"` atom.

The tetrahedral structure is similar to that of `"CH"_2"Cl"_2`

It can't possibly be chiral.

So tetrahedral `["NiCl"_2"Br"_2]^(2-)` has no stereoisomers.