Question

Mixing SbCl3 and GaCl3 in a 1;1 molar ratio (using liquid sulfur dioxide as a solvent) gives a solid ionic compound of empirical formula GaSbCl6. A controversy arises over whether this compound is (SbCl2 )(GaCl4 ) 1 2 or (GaCl2 )(SbCl4 ). 1 2 (a) Predict the molecular structures of the two anions. (b) It is learned that the cation in the compound has a bent structure. Based on this fact, which formulation is more likely to be correct

Answer 1

Answer:

a) [GaCl4]^- Tetrahedral

[SbCl4]^- See saw

b) [SbCl2]^+ [GaCl4]^-

Explanation:

If we look at the anion, [GaCl4]^-, we can see that it contains four electron domains and no lone pairs so we usually expect it to be in a terahedral geometry.

Looking at [SbCl4]^-, there are five electron domains with one lone pair. It is usually expected to exhibit a seesaw molecular geometry.

[SbCl2]^+ (18 valence electrons) is known to possess a bent geometry(due to the presence of a lone pair of electrons on the central atom, Sb) while [GaCl2]^+ (16 valence electrons) is known to possess a linear geometry.

Since  it was stated in the question that the cation must posses a bent geometry, then the correct structure is; [SbCl2]^+ [GaCl4]^-