Question

A species that is isoelectronic with the nitrate ion and hence would have the same shape is [1] [2] [3] [4] [5] sulphur trioxide sulphite ion phosphine, PH: water chlorite ion

Answer 1

[1] sulphur trioxide

Step-by-step explanation:

Isoelectronic species have the same number of valence electrons.

Valence electrons in nitrate (NO₃⁻):

5e- (N) + (3 x 6e-)(3xO) + 1e- (charge) = 24e-

Valence electrons in sulphur trioxide (SO₃):

6e- (S) + (3 x 6e-)(3xO) = 24e-

Valence electrons in sulphite (SO₃²⁻):

6e- (S) + (3 x 6e-)(3xO) + 2e- (charge) = 26e-

Valence electrons in phosphine (PH₃):

5e- (P) + (3 x 1e-)(3xH) = 8e-

Valence electrons in water (H₂O):

6e- (O) + (2 x 1e-)(2xH) = 8e-

Valence electrons in chlorite (ClO₂⁻):

7e- (Cl⁻) + (2 x 6e-)(2xO) + 1e- (charge) = 20e-

The only species isoelectronic with nitrate is sulphur trioxide. Both have trigonal planar geoemetry.